diff --git a/spec/spec.md b/spec/spec.md
index dff2f24..4b5d100 100644
--- a/spec/spec.md
+++ b/spec/spec.md
@@ -64,7 +64,7 @@ Chains of ACDCs that merely provide proof-of-authorship (authenticity) of data m
 
 ACDCs act as securely attributed (authentic) fragments of a distributed property graph (PG) [[56]] [[57]]. Thus, ACDCs may be used to construct knowledge graphs expressed as property graphs [[58]]. ACDCs enable securely-attributed and privacy-protecting knowledge graphs. Semantically modulated verifiable provenanceable graphs enable authenticatable, delegable, attenuable, and aggregable authorizations and attributions.
 
-The ACDC specification (including its disclosure mechanisms) leverages two primary cryptographic operations, namely digests and digital signatures [[48]] [[52]]. These operations, when used in an ACDC, must have a security level, cryptographic strength, or entropy of approximately 128 bits [[53]]. (See [Annex A](#cryptographic-strength-and-security) for a discussion of cryptographic strength and security)
+The ACDC specification (including its disclosure mechanisms) leverages two primary cryptographic operations, namely digests and digital signatures [[48]] [[52]]. These operations, when used in an ACDC, MUST have a security level, cryptographic strength, or entropy of approximately 128 bits (nominally) [[53]]. (See [Annex A](#cryptographic-strength-and-security) for a discussion of cryptographic strength and security)
 
 An important property of high-strength cryptographic digests is that a verifiable cryptographic commitment (such as a digital signature) to the digest of some data is equivalent to a commitment to the data itself. The digest enables confidentiality because secure attribution of the commitment to the digest may be verified without disclosing the digested data. Later, confidential disclosure of the digested data can be verified against the digest. ACDCs leverage this property to enable compact chains of ACDCs that commit to (anchor or seal) data via digests. The data actually contained in an ACDC, therefore, may be merely its digest. The digested data may thereby be equivalently but more compactly and confidentially authenticated and authorized by the chain of ACDCs.
 
@@ -88,7 +88,7 @@ available at
 If source code is included in the specification, that code is subject to the
 [Apache 2.0 license](https://www.apache.org/licenses/LICENSE-2.0.txt) unless otherwise marked. In the case of any conflict or
 confusion within this specification between the OWF Contributor License 
-and the designated source code license, the terms of the OWF Contributor License shall apply.
+and the designated source code license, the terms of the OWF Contributor License MUST apply.
 
 These terms are inherited from the Technical Stack Working Group at the Trust over IP Foundation. [Working Group Charter](https://trustoverip.org/wp-content/uploads/TSWG-2-Charter-Revision.pdf)
 
@@ -116,7 +116,14 @@ Implementation design of a protocol-based data container specification that enab
 
 [//]: # (:::)
 
-This document has no normative references.
+[a]. IETF RFC-2119 Key words for use in RFCs to Indicate Requirement Levels
+[a]: https://www.rfc-editor.org/rfc/rfc2119.txt
+
+[b]. IETF RFC-4648 Base64 
+[b]: https://www.rfc-editor.org/rfc/rfc4648.txt
+
+[c]. IETF RFC-3339 DateTime 
+[c]: https://www.rfc-editor.org/rfc/rfc3339.txt
 
 
 ## Terms and Definitions
@@ -288,12 +295,12 @@ ISO and IEC maintain terminological databases for use in standardization at the
 
 An ACDC may be modeled abstractly as a nested `key: value` mapping. To avoid confusion with the cryptographic use of the term key,  the term field is used instead to refer to a mapping pair and the terms field label and field value for each member of a pair. These pairs can be represented by two tuples, e.g., `(label, value)`. This terminology can be qualified, when necessary, by using the term field map to reference such a mapping. Field maps may be nested where a given field value is itself a reference to another field map. A nested set of fields is called a nested field map or simply a nested map for short. 
 
-A field may be represented by a [[ref: Framing Code]] or block delimited serialization.  In a block delimited serialization, such as JSON, each field map is represented by an object block with block delimiters such as `{}` [[8]] [[7]] [[9]]. Given this equivalence, the term block or nested block also may be used as synonymous with field map or nested field map. In many programming languages, a field map is implemented as a dictionary or hash table in order to enable performant asynchronous lookup of a field value from its field label. Reproducible serialization of field maps requires a canonical ordering of those fields. One such canonical ordering is called insertion or field creation order. A list of `(field, value)` pairs provides an ordered representation of any field map. Most programming languages now support ordered dictionaries or hash tables that provide reproducible iteration over a list of ordered field `(label, value)` pairs where the ordering is the insertion or field creation order. This enables reproducible round-trip serialization/deserialization of field maps.  ACDCs depend on insertion ordered field maps for canonical serialization/deserialization. ACDCs support multiple serialization types, namely JSON, CBOR, MGPK, and CESR but for the sake of simplicity, JSON only will be used for examples [[8]] [[7]]. The basic set of normative field labels in ACDC field maps is defined in the following table.
+A field may be represented by a [[ref: Framing Code]] or block delimited serialization.  In a block-delimited serialization, such as JSON, each field map is represented by an object block with block delimiters such as `{}` [[8]] [[7]] [[9]]. Given this equivalence, the term block or nested block also may be used as synonymous with field map or nested field map. In many programming languages, a field map is implemented as a dictionary or hash table in order to enable performant asynchronous lookup of a field value from its field label. Reproducible serialization of field maps requires a canonical ordering of those fields. One such canonical ordering is called insertion or field creation order. A list of `(field, value)` pairs provides an ordered representation of any field map. Most programming languages now support ordered dictionaries or hash tables that provide reproducible iteration over a list of ordered field `(label, value)` pairs where the ordering is the insertion or field creation order. This enables reproducible round-trip serialization/deserialization of field maps without having to reorder them using lexicographic (alphabetical) order.  ACDCs MUST use insertion-ordered field maps for canonical serialization/deserialization. ACDCs support multiple serialization types, namely JSON, CBOR, MGPK, and CESR but for the sake of simplicity, JSON only will be used for examples [[8]] [[7]]. The basic set of normative field labels in ACDC field maps is defined in the following table.
 
 
 ### Top-Level fields
 
-The following table defines the top-level fields in an ACDC and their order of appearance. Some fields are optional but all fields that appear must appear in a defined order.
+The following table defines the top-level fields in an ACDC and their order of appearance. Some fields are OPTIONAL but all fields that appear MUST appear in a defined order. This section defines which fields are REQUIRED and which are OPTIONAL.
 
 | Label | Title | Description |
 |:-:|:--|:--|
@@ -310,16 +317,16 @@ The following table defines the top-level fields in an ACDC and their order of a
 
 #### Field ordering
 
-When present, the top-level fields shall appear in the following order: `[v, d, u, i, rd, s, a, A, e, r]`. 
+When present, the top-level fields MUST appear in the following order: `[v, d, u, i, rd, s, a, A, e, r]`. 
 
 #### Required fields
 
-The following fields are required `[v, d, i, s]`. 
+The following fields are REQUIRED `[v, d, i, s]` i.e. they MUST appear in any ACDC. 
 
 ### Other reserved fields
 
-The following table defines non-top-level fields whose labels are reserved. 
-These appear at other levels besides the top-level of an ACDC. 
+The following table defines non-top-level fields whose labels MUST be reserved. 
+These MAY appear at other levels besides the top-level of an ACDC. 
 
 | Label | Title | Description |
 |:-:|:--|:--|
@@ -333,24 +340,24 @@ These appear at other levels besides the top-level of an ACDC.
 
 ### Compact labels
 
-The primary field labels are compact in that they use only one or two characters. ACDCs are meant to support resource-constrained applications such as supply chain or IoT (Internet of Things) applications. Compact labels better support resource-constrained applications in general. With compact labels, the over-the-wire verifiable signed serialization consumes a minimum amount of bandwidth. Nevertheless, without loss of generality, a one-to-one normative semantic overlay using more verbose expressive field labels may be applied to the normative compact labels after verification of the over-the-wire serialization. This approach better supports bandwidth and storage constraints on transmission while not precluding any later semantic post-processing. This is a well-known design pattern for resource-constrained applications.
+The primary field labels are compact in that they MUST use only one or at most two characters. ACDCs are meant to support resource-constrained applications such as supply chain or IoT (Internet of Things) applications. Compact labels better support resource-constrained applications in general. With compact labels, the over-the-wire verifiable signed serialization consumes a minimum amount of bandwidth. Nevertheless, without loss of generality, a one-to-one normative semantic overlay using more verbose expressive field labels may be applied to the normative compact labels after verification of the over-the-wire serialization. This approach better supports bandwidth and storage constraints on transmission while not precluding any later semantic post-processing. This is a well-known design pattern for resource-constrained applications.
 
 ### Version String field
 
-The Version String, `v`, field shall be the first field in any top-level ACDC field map encoded in JSON, CBOR, or MGPK as a Message body [[spec: RFC4627]] [[spec: RFC4627]] [[12]] [[13]] [[14]]. It provides a regular expression target for determining a serialized field map's serialization format and size (character count) constituting an ACDC message body. A Stream parser may use the Version String to extract and deserialize (deterministically) any serialized Stream of ACDC Message bodies. Each ACDC Message body in a Stream may use a different serialization type. The format for the Version String field value is defined in the CESR specification [[1]]. 
+The Version String, `v`, field MUST be the first field in any top-level ACDC field map encoded in JSON, CBOR, or MGPK [[spec: RFC4627]] [[spec: RFC4627]] [[12]] [[13]] [[14]].  It provides a regular expression target for determining a serialized field map's serialization format and size (character count) constituting an ACDC message body. A Stream parser SHOULD use the Version String to extract and deserialize (deterministically) any serialized Stream of ACDC Message bodies. Each ACDC Message body in a Stream MAY use a different serialization type. The format for the Version String field value is defined in the CESR specification [[1]]. 
 
-The protocol field, `PPPP` value in the Version String shall be `ACDC` for the ACDC protocol. The version field, `VVV`, shall encode the current version of the ACDC protocol [[1]].
+The protocol field, `PPPP` value in the Version String MUST be `ACDC` for the ACDC protocol. The version field, `VVV`, MUST encode the current version of the ACDC protocol [[1]].
 
 ##### Legacy Version String field format
 
-Compliant ACDC version 2.XX implementations shall support the old ACDC version 1.x Version String format to properly verify Message bodies created with 1.x format events. The old version 1.X Version String format is defined in the CESR specification [[1]]. The protocol field, `PPPP` value in the version string shall be `ACDC` for the ACDC protocol. The version field, `vv`, shall encode the old version of the ACDC protocol [[1]].
+Compliant ACDC version 2.XX implementations MUST support the old ACDC version 1.x Version String format to properly verify Message bodies created with 1.x format events. The old version 1.X Version String format is defined in the CESR specification [[1]]. The protocol field, `PPPP` value in the version string MUST be `ACDC` for the ACDC protocol. The version field, `vv`, MUST encode the old version of the ACDC protocol [[1]].
 
 
 ### Self-addressing identifier (SAID) fields
 
-Some fields in ACDCs may have for their value either a field map or a SAID. A SAID follows the SAID protocol [[3]]. A SAID is a special type of cryptographic digest of its encapsulating field map (block). The encapsulating block of a SAID is called a SAD (Self-addressed data). Using a SAID as a field value enables a more compact but secure representation of the associated block (SAD) from which the SAID is derived. Any nested field map that includes a SAID field (i.e., is, therefore, a SAD) may be compacted into its SAID. The uncompacted blocks for each associated SAID may be attached or cached to optimize bandwidth and availability without decreasing security.
+Some fields in ACDCs MAY have for their value either a field map or a SAID. A SAID follows the SAID protocol [[3]]. A SAID is a special type of cryptographic digest of its encapsulating field map (block). The encapsulating block of a SAID is called a SAD (Self-addressed data). Using a SAID as a field value enables a more compact but secure representation of the associated block (SAD) from which the SAID is derived. Any nested field map that includes a SAID field (i.e., is, therefore, a SAD) MAY be compacted into its SAID. The uncompacted blocks for each associated SAID MAY be attached or cached to optimize bandwidth and availability without decreasing security.
 
-Several top-level ACDC fields may have for their value either a serialized field map or the SAID of that field map. Each SAID provides a stable, universal, cryptographically verifiable, and agile reference to its encapsulating block (serialized field map). These include the `d`, and `rd` fields. Moreover, the value of top-level `s`, `a`, `e`, and `r` fields may be replaced by the SAID of their associated field map. When replaced by their SAID, these top-level sections are in compact form.
+Several top-level ACDC fields MAY have for their value either a serialized field map or the SAID of that field map. Each SAID provides a stable, universal, cryptographically verifiable, and agile reference to its encapsulating block (serialized field map). These include the `d`, and `rd` fields. Moreover, the value of top-level `s`, `a`, `e`, and `r` fields MAY be replaced by the SAID of their associated field map. When replaced by their SAID, these top-level sections are in compact form.
 
 Recall that a cryptographic commitment (such as a digital signature or cryptographic digest) on a given digest with sufficient cryptographic strength, including collision resistance [[34]] [[35]], is equivalent to a commitment to the block from which the given digest was derived.  Specifically, a digital signature on a SAID makes a verifiable cryptographic non-repudiable commitment that is equivalent to a commitment on the full serialization of the associated block from which the SAID was derived. This enables reasoning about ACDCs in whole or in part via their SAIDs in a fully interoperable, verifiable, compact, and secure manner. This also supports the well-known bow-tie model of Ricardian Contracts [[43]]. This includes reasoning about the whole ACDC given by its top-level SAID, `d`, field, as well as reasoning about any nested sections using their SAIDs.
 
@@ -363,23 +370,23 @@ When present, the registry SAID, `rd` field value is the SAID of the initializin
 
 The purpose of the UUID, `u`, field in any block is to provide sufficient entropy to the SAID, `d`, field of the associated block to make computationally infeasible any brute force attacks on that block that attempt to discover the block contents from the schema and the SAID. The UUID, `u`, field may be considered a salty nonce [[29]]. Without the entropy provided the UUID, `u`, field, an adversary may be able to reconstruct the block contents merely from the SAID of the block and the [[ref: Schema]] of the block using a rainbow or dictionary attack on the set of field values allowed by the Schema [[30]] [[31]]. The effective security level, entropy, or cryptographic strength of the schema-compliant field values may be much less than the cryptographic strength of the SAID digest. Another way of saying this is that the cardinality of the power set of all combinations of allowed field values may be much less than the cryptographic strength of the SAID. Thus, an adversary could successfully discover via brute force the exact block by creating digests of all the elements of the power set which may be small enough to be computationally feasible instead of inverting the SAID itself. Sufficient entropy in the `u` field ensures that the cardinality of the power set allowed by the schema is at least as great as the entropy of the SAID digest algorithm itself.
 
-A UUID, `u` field may optionally appear in any block (field map) at any level of an ACDC. Whenever a block in an ACDC includes a UUID, `u`, field then its associated SAID, `d`, field makes a blinded commitment to the contents of that block. The UUID, `u`, field is the blinding factor. This makes that block securely partially disclosable or even selectively disclosable notwithstanding disclosure of the associated Schema of the block. The block contents can only be discovered given disclosure of the included UUID field. Likewise, when a UUID, `u`, field appears at the top level of an ACDC then that top-level SAID, `d`, field makes a blinded commitment to the contents of the whole ACDC itself. Thus, the whole ACDC, not merely some block within the ACDC, may be disclosed in a privacy-preserving (correlation minimizing).
+A UUID, `u` field MAY optionally appear in any block (field map) at any level of an ACDC. Whenever a block in an ACDC includes a UUID, `u`, field then its associated SAID, `d`, field makes a blinded commitment to the contents of that block. The UUID, `u`, field is the blinding factor. This makes that block securely partially disclosable or even selectively disclosable notwithstanding disclosure of the associated Schema of the block. The block contents can only be discovered given disclosure of the included UUID field. Likewise, when a UUID, `u`, field appears at the top level of an ACDC then that top-level SAID, `d`, field makes a blinded commitment to the contents of the whole ACDC itself. Thus, the whole ACDC, not merely some block within the ACDC, MAY be disclosed in a privacy-preserving (correlation minimizing).
 
 ### Autonomic IDentifier (AID) fields
 
-Some fields, such as the `i`, Issuer identifier field, must each have an [[ref: AID]] as its value. An AID is a fully qualified Self-certifying Identifier (SCID) that follows the KERI protocol [[2]].  An AID is derived from one or more `(public, private)` key pairs using asymmetric or public-key cryptography to create verifiable digital signatures [[52]]. Each AID has a set of one or more Controllers who each control a private key. By virtue of their private key(s), the Controllers may make statements on behalf of the associated AID backed by uniquely verifiable commitments via digital signatures on those statements. Any entity then may verify those signatures using the associated set of public keys. No shared or trusted relationship between the Controllers and Verifiers is required. The verifiable key state for AIDs is established with the KERI protocol [[2]]. The use of AIDs enables ACDCs to be used in a portable but securely attributable, fully decentralized manner in an ecosystem that spans trust domains.
+Some fields, such as the `i`, Issuer identifier field, MUST each have an [[ref: AID]] as its value. An AID is a fully qualified Self-certifying Identifier (SCID) that follows the KERI protocol [[2]].  An AID MUST be derived from one or more `(public, private)` key pairs using asymmetric or public-key cryptography to create verifiable digital signatures [[52]]. Each AID SHOULD have set of one or more Controllers who each control a private key. By virtue of their private key(s), the Controllers MAY make statements on behalf of the associated AID backed by uniquely verifiable commitments via digital signatures on those statements. Any entity then MAY verify those signatures using the associated set of public keys. No shared or trusted relationship between the Controllers and Verifiers is REQUIRED. The verifiable key state for AIDs MUST be established with the KERI protocol [[2]]. The use of AIDs enables ACDCs to be used in a portable but securely attributable, fully decentralized manner in an ecosystem that spans trust domains.
 
 ### Namespaced AIDs
 
-Because KERI is agnostic about the namespace for any particular AID, different namespace standards may be used to express KERI AIDs or identifiers derived from AIDs as the value of these AID related fields in an ACDC. Some of the examples below use the W3C DID namespace specification with the `did:keri` method [[ref: DIDK_ID]. However, the examples would have the same validity from a KERI perspective if some other supported namespace was used or no namespace was used at all. The latter case consists of a bare KERI AID (identifier prefix) expressed in CESR format [[1]].
+Because KERI is agnostic about the namespace for any particular AID, different namespace standards MAY be used to express KERI AIDs or identifiers derived from AIDs as the value of these AID related fields in an ACDC. Some of the examples below use the W3C DID namespace specification with the `did:keri` method [[ref: DIDK_ID]. However, the examples would have the same validity from a KERI perspective if some other supported namespace was used or no namespace was used at all. The latter case consists of a bare KERI AID (identifier prefix) expressed in CESR format [[1]].
 
 ### Attribute field
 
-The top-level Attribute section `a`, field value may have as its value a nested field map. Each level of nesting may be fully expanded or represented by its SAID. When present, the `a` field value provides the so-called payload data of the ACDC. The `a` field syntax is described in more detail below. An ACDC shall not have both an `a` field and an `A` field (see next section) when it has either.
+The top-level Attribute section `a`, field value MAY have as its value a nested field map. Each level of nesting MAY be fully expanded or represented by its SAID. When present, the `a` field value provides the so-called payload data of the ACDC. The `a` field syntax is described in more detail below. An ACDC MUST not have both an `a` field and an `A` field (see next section) when it has either.
 
 ### Selectively disclosable Attribute aggregate field
 
-The top-level selectively disclosable Attribute aggregate section, `A`, field value is an aggregate of cryptographic commitments used to make a commitment to a set (bundle) of selectively disclosable Attributes. The value of the Attribute aggregate, `A`, field depends on the type of Selective Disclosure mechanism employed. For example, the aggregate value could be the cryptographic digest of the concatenation of an ordered set of cryptographic digests, a Merkle tree root digest of an ordered set of cryptographic digests, or a cryptographic accumulator. The Selective Disclosure mechanisms are described in detail in the Selective Disclosure section. When present, the `A` field value provides the so-called payload data of the ACDC. The `A` field syntax is described in more detail below. An ACDC shall not have both an `a` field and an `A` field (see next section) when it has either.
+The top-level selectively disclosable Attribute aggregate section, `A`, field value is an aggregate of cryptographic commitments used to make a commitment to a set (bundle) of selectively disclosable Attributes. The value of the Attribute aggregate, `A`, field depends on the type of Selective Disclosure mechanism employed. For example, the aggregate value could be the cryptographic digest of the concatenation of an ordered set of cryptographic digests, a Merkle tree root digest of an ordered set of cryptographic digests, or a cryptographic accumulator. The Selective Disclosure mechanisms are described in detail in the Selective Disclosure section. When present, the `A` field value provides the so-called payload data of the ACDC. The `A` field syntax is described in more detail below. An ACDC MUST not have both an `a` field and an `A` field (see next section) when it has either.
 
 
 ### Edge field
@@ -388,7 +395,7 @@ The top-level Edge section `e` field value makes a cryptographically verifiable
 
 ### Rule field
 
-The top-level Rule section `r`, field value provides both human and machine readable legal language that may be associated with the ACDC. This is a type of Ricardian contract. The `r` field syntax is described in more detail below.
+The top-level Rule section `r`, field value provides both human and machine readable legal language that MAY be associated with the ACDC. This is a type of Ricardian contract. The `r` field syntax is described in more detail below.
 
 
 ### Field ordering
@@ -397,27 +404,27 @@ The ordering of the top-level fields when present in an ACDC must be as follows,
 
 ## ACDC variants
 
-There are several variants of ACDCs determined by the presence/absence of certain fields and/or the value of those fields when used in combination. The primary ACDC variants are public, private, metadata, and bespoke. A given variant may be Targeted (Untargeted). 
+There are several variants of ACDCs determined by the presence/absence of certain fields and/or the value of those fields when used in combination. The primary ACDC variants are public, private, metadata, and bespoke. A given variant MAY be Targeted (Untargeted). 
 
 All the variants have two alternate forms, compact and non-compact. In the compact form of any variant, the values of the top-level fields for the Schema, Attribute, Attribute aggregate, Edge, and Rule sections are the SAIDs (digests) of the corresponding expanded (non-compact) form of each section {{SAID}}. Additional variants arise from the presence or absence of different fields inside the Attribute or Attribute aggregate section. 
 
-At the top level, the presence (absence), of the UUID, `u`, field produces two additional variant combinations. These are private (public), respectively. In addition, a present but empty UUID, `u`, field produces a private metadata variant. Furthermore, a given variant may be either Targeted or Untargeted based on the presence of the Issuee field in the Attribute or Attribute aggregate sections. Similarly, any variant with an Attribute section may have nested sub-blocks within the Attribute section that are either compact or non-compact. This enables nested Partial Disclosure. The type of disclosure a given variant supports may be dependent on how the different sections appear in the ACDC.
+At the top level, the presence (absence), of the UUID, `u`, field produces two additional variant combinations. These are private (public), respectively. In addition, a present but empty UUID, `u`, field produces a private metadata variant. Furthermore, a given variant MAY be either Targeted or Untargeted based on the presence of the Issuee field in the Attribute or Attribute aggregate sections. Similarly, any variant with an Attribute section MAY have nested sub-blocks within the Attribute section that are either compact or non-compact. This enables nested Partial Disclosure. The type of disclosure a given variant supports MAY be dependent on how the different sections appear in the ACDC.
 
 An overview of each variant is explained below.
 
 ### Most compact form SAID
 
-As defined in the Schema section below, ACDC variants are defined by composable JSON Schema. The primary Operator for such composition is `oneOf`. The use of the `oneOf` operator for an ACDC schema enables the use of any combination of compacted/uncompacted top-level sections as well as nested blocks. When compact, any section or nested block may be represented merely by its [[10]] [[39]].
+As defined in the Schema section below, ACDC variants are defined by composable JSON Schema. The primary Operator for such composition is `oneOf`. The use of the `oneOf` operator for an ACDC schema enables the use of any combination of compacted/uncompacted top-level sections as well as nested blocks. When compact, any section or nested block MAY be represented merely by its SAID [[10]] [[39]].
 
-However, for the sake of verifiability, each section or block that is compactable shall have only one SAID regardless of how many different variants its `oneOf` compositions allow. Therefore, there must be one and only one unambiguous way to compute the SAID of a compactifiable section or block with compactifiable nested blocks. This is called the "most compact form" SAID computation algorithm. The basis of the algorithm is that the SAID of a given block is verifiable against that block in expanded form but that SAID can be embedded in an enclosing block in compact form. The SAID of the enclosing block makes a verifiable commitment to the given block via the appearance of only the SAID of the given block. The SAID of the "most compact form" can be computed by a depth-first search.  First, compute the SAIDs of the expanded leaf nodes of the tree, then compact the leaves, then compute the SAIDs of their enclosing blocks, then compact those, and so on until the trunk has been reached.
+However, for the sake of verifiability, each section or block that is compactable MUST have only one SAID regardless of how many different variants its `oneOf` compositions allow. Therefore, there MUST be one and only one unambiguous way to compute the SAID of a compactifiable section or block with compactifiable nested blocks. This is called the "most compact form" SAID computation algorithm. The basis of the algorithm is that the SAID of a given block is verifiable against that block in expanded form but that SAID can be embedded in an enclosing block in compact form. The SAID of the enclosing block makes a verifiable commitment to the given block via the appearance of only the SAID of the given block. The SAID of the "most compact form" can be computed by a depth-first search.  First, compute the SAIDs of the expanded leaf nodes of the tree, then compact the leaves, then compute the SAIDs of their enclosing blocks, then compact those, and so on until the trunk has been reached.
 
 To verify the SAID, just reverse the process. First, expand a given block, verify its SAID, expand its enclosed blocks, verify their SAIDs, and so on as deep as needed or until the leaves are reached. The main advantage of "most compact form" SAID computation is that it enables verification of portions of a set of nested compactifiable subblocks against their SAIDs without requiring that the whole tree of subblocks be exposed. This is essential to Graduated Disclosure.
 
 The algorithm for computing the “most compact form" of a block for computing its SAID is as follows.
 
-- A SAIDed block is any block that has a SAID field `d` when in block-level expanded form. Any SAIDed block is compactifiable into the compact form consisting of a string field whose value is the SAID of the block-level expanded form and whose label is the block label. This compact form shall appear as the first variant in the `oneOf` subschema list for its labeled field. In block-level expanded form, all fields with non-SAIDed subblock values are fully expanded, whereas all fields with SAIDed subblocks are represented in compact form. The latter requires first representing each SAIDed subblock in block-level expanded form, computing its SAID, and then using that SAID to represent it in compact form.
+- A SAIDed block is any block that has a SAID field `d` when in block-level expanded form. Any SAIDed block is compactifiable into the compact form consisting of a string field whose value is the SAID of the block-level expanded form and whose label is the block label. This compact form MUST appear as the first variant in the `oneOf` subschema list for its labeled field. In block-level expanded form, all fields with non-SAIDed subblock values are fully expanded, whereas all fields with SAIDed subblocks are represented in compact form. The latter requires first representing each SAIDed subblock in block-level expanded form, computing its SAID, and then using that SAID to represent it in compact form.
 
-- A SAIDed block that does not have any nested SAIDed subblocks as fields is a leaf block. Its SAID shall be computed on the full expanded representation of the block. It may then be represented in the compact form but using the SAID computed on its fully expanded form. To clarify, because the leaf has no SAIDed subblocks, its block-level expanded form is fully expanded, including any fields with subblocks. This is a concern when it has subblocks whose schema has `oneOf` composition variants that omit any details. This is the case for a simple-compact edge or a simple-compact rule (see below under the Edge and Rule sections), which are each a nested (non-SAIDed) subblock with a non-SAID-based compact `oneOf` variant. These are special cases, and the most detailed variant of the subblock shall be the fully expanded form. 
+- A SAIDed block that does not have any nested SAIDed subblocks as fields is a leaf block. Its SAID MUST be computed on the full expanded representation of the block. It MAY then be represented in the compact form but using the SAID computed on its fully expanded form. To clarify, because the leaf has no SAIDed subblocks, its block-level expanded form is fully expanded, including any fields with subblocks. This is a concern when it has subblocks whose schema has `oneOf` composition variants that omit any details. This is the case for a simple-compact edge or a simple-compact rule (see below under the Edge and Rule sections), which are each a nested (non-SAIDed) subblock with a non-SAID-based compact `oneOf` variant. These are special cases, and the most detailed variant of the subblock MUST be the fully expanded form. 
 
 - The computation of the SAID of any SAIDed block is as follows. 
     - Fully expand any field within the block whose value is a Non-SAIDed sub-block.
@@ -437,17 +444,17 @@ The top-level section field values of a Compact ACDC are the SAIDs of each uncom
 
 ### Public ACDC
 
-Given that there is no top-level UUID, `u`, field in an ACDC, then knowledge of both the schema of the ACDC and the top-level SAID, `d`, field may enable the discovery of the remaining contents of the ACDC via a rainbow table attack [[30]] [[31]]. Therefore, although the top-level, `d`, field is a cryptographic digest, it may not securely blind the contents of the ACDC when knowledge of the Schema is available.  The field values may be discoverable. Consequently, any cryptographic commitment to the top-level SAID, `d`, field may provide a fixed point of correlation potentially to the ACDC field values themselves in spite of non-disclosure of those field values. Thus, an ACDC without a top-level UUID, `u`, field must be considered a public (non-confidential) ACDC.
+Given that there is no top-level UUID, `u`, field in an ACDC, then knowledge of both the schema of the ACDC and the top-level SAID, `d`, field may enable the discovery of the remaining contents of the ACDC via a rainbow table attack [[30]] [[31]]. Therefore, although the top-level, `d`, field is a cryptographic digest, it may not securely blind the contents of the ACDC when knowledge of the Schema is available.  The field values may be discoverable. Consequently, any cryptographic commitment to the top-level SAID, `d`, field may provide a fixed point of correlation potentially to the ACDC field values themselves in spite of non-disclosure of those field values. Thus, an ACDC without a top-level UUID, `u`, field SHOULD be considered a public (non-confidential) ACDC.
 
 ### Private ACDC
 
-Given a top-level UUID, `u`, field, whose value has sufficient cryptographic entropy, then the top-level SAID, `d`, field of an ACDC may provide a secure cryptographic digest that blinds the contents of the ACDC [[48]]. An adversary when given both the Schema of the ACDC and the top-level SAID, `d`, field, is not able to discover the remaining contents of the ACDC in a computationally feasible manner such as through a rainbow table attack [[30]] [[31]]. Therefore, the top-level, UUID, `u`, field may be used to securely blind the contents of the ACDC notwithstanding knowledge of the Schema and top-level, SAID, `d`, field.  Moreover, a cryptographic commitment to that that top-level SAID, `d`, field does not provide a fixed point of correlation to the other ACDC field values themselves unless and until there has been a disclosure of those field values. Thus, an ACDC with a sufficiently high entropy top-level UUID, `u`, field may be considered a private (confidential) ACDC. enables a verifiable commitment to the top-level SAID of a private ACDC to be made prior to the disclosure of the details of the ACDC itself without leaking those contents. This is called Partial Disclosure. Furthermore, the inclusion of a UUID, `u`, field in a block also enables Selective Disclosure mechanisms described later in the section on [Selective Disclosure](#selective-disclosure).
+Given a top-level UUID, `u`, field, whose value has sufficient cryptographic entropy, then the top-level SAID, `d`, field of an ACDC could provide a secure cryptographic digest that blinds the contents of the ACDC [[48]]. An adversary when given both the Schema of the ACDC and the top-level SAID, `d`, field, is not able to discover the remaining contents of the ACDC in a computationally feasible manner such as through a rainbow table attack [[30]] [[31]]. Therefore, the top-level, UUID, `u`, field could be used to securely blind the contents of the ACDC notwithstanding knowledge of the Schema and top-level, SAID, `d`, field.  Moreover, a cryptographic commitment to that top-level SAID, `d`, field does not provide a fixed point of correlation to the other ACDC field values themselves unless and until there has been a disclosure of those field values. Thus, an ACDC with a sufficiently high entropy top-level UUID, `u`, field MAY be considered a private (confidential) ACDC. This enables a verifiable commitment to the top-level SAID of a private ACDC to be made prior to the disclosure of the details of the ACDC itself without leaking those contents. This is called Partial Disclosure. Furthermore, including a UUID, `u`, field in a block also enables Selective Disclosure mechanisms described later in the section on [Selective Disclosure](#selective-disclosure).
 
 ### Metadata ACDC 
 
-An empty, top-level UUID, `u`, field appearing in an ACDC indicates that the ACDC is a metadata ACDC. The purpose of a metadata ACDC is to provide a mechanism for a Discloser to make cryptographic commitments to the metadata of a yet to be disclosed private ACDC without providing any point of correlation to the actual top-level SAID, `d`, field of that yet to be disclosed ACDC. The top-level SAID, `d`, field, of the metadata ACDC, is cryptographically derived from an ACDC with an empty top-level UUID, `u`, field so its value will necessarily be different from that of an ACDC with a high entropy top-level UUID, `u`, field value. Nonetheless, the Discloser may make a non-repudiable cryptographic commitment to the metadata SAID in order to initiate a contractually protected exchange without leaking correlation to the actual ACDC to be disclosed [[44]. A Disclosee may verify the other metadata information in the metadata ACDC before agreeing to any restrictions imposed by the future disclosure. The metadata includes the Issuer, the Schema, the provenanced Edges, and the Rules (terms-of-use). The top-level Attribute section, `a`, field value, or the top-level Attribute aggregate, `A` field value of a metadata ACDC may be empty so that its value is not correlatable across disclosures (presentations). Should the potential Disclosee refuse to agree to the Rules, then the Discloser has not leaked the SAID of the actual ACDC or the SAID of the Attribute block that would have been disclosed.
+An empty, top-level UUID, `u`, field appearing in an ACDC indicates that the ACDC is a metadata ACDC. The purpose of a metadata ACDC is to provide a mechanism for a Discloser to make cryptographic commitments to the metadata of a yet to be disclosed private ACDC without providing any point of correlation to the actual top-level SAID, `d`, field of that yet to be disclosed ACDC. The top-level SAID, `d`, field, of the metadata ACDC, is cryptographically derived from an ACDC with an empty top-level UUID, `u`, field so its value will necessarily be different from that of an ACDC with a high entropy top-level UUID, `u`, field value. Nonetheless, the Discloser MAY make a non-repudiable cryptographic commitment to the metadata SAID in order to initiate a contractually protected exchange without leaking correlation to the actual ACDC to be disclosed [[44]. A Disclosee MAY verify the other metadata information in the metadata ACDC before agreeing to any restrictions imposed by the future disclosure. The metadata includes the Issuer, the Schema, the provenanced Edges, and the Rules (terms-of-use). The top-level Attribute section, `a`, field value, or the top-level Attribute aggregate, `A` field value of a metadata ACDC MAY be empty so that its value is not correlatable across disclosures (presentations). Should the potential Disclosee refuse to agree to the Rules, then the Discloser has not leaked the SAID of the actual ACDC or the SAID of the Attribute block that would have been disclosed.
 
-Given the metadata ACDC, the potential Disclosee is able to verify the Issuer, the Schema, the provenanced Edges, and Rules prior to agreeing to the Rules.  Similarly, an Issuer may use a metadata ACDC to get agreement to a contractual waiver expressed in the Rules section with a potential Issuee prior to issuance. Should the Issuee refuse to accept the terms of the waiver, then the Issuer has not leaked the SAID of the actual ACDC that would have been issued nor the SAID of its attributes block nor the Attribute values themselves.
+Given the metadata ACDC, the potential Disclosee is able to verify the Issuer, the Schema, the provenanced Edges, and Rules prior to agreeing to the Rules.  Similarly, an Issuer MAY use a metadata ACDC to get agreement to a contractual waiver expressed in the Rules section with a potential Issuee prior to issuance. Should the Issuee refuse to accept the terms of the waiver, then the Issuer has not leaked the SAID of the actual ACDC that would have been issued nor the SAID of its attributes block nor the Attribute values themselves.
 
 When a metadata ACDC is disclosed (presented), only the Discloser's signature(s) is attached, not the Issuer's signature(s). This precludes the Issuer's signature(s) from being used as a point of correlation until after the Disclosee has agreed to the terms in the rule section. When Contractually Protected Disclosure is used, the Issuer's signature(s) is not disclosed to the Disclosee until after the Disclosee has agreed to the terms. The Disclosee is protected from a forged Discloser because, ultimately, verification of the disclosed ACDC will fail if the Discloser does not eventually provide verifiable Issuer's signatures. Nonetheless, should the potential Disclosee not agree to the terms of the disclosure expressed in the Rules section, then the Issuer's signature(s) is not leaked.
 
@@ -641,75 +648,75 @@ The schema for the Compact private ACDC example above is provided below.
 
 #### Type-is-schema
 
-Notable is the fact that no top-level type fields exist in an ACDC. This is because the [[ref: Schema]], `s`, field itself is the type field for the ACDC and its parts. ACDCs follow the design principle of separation of concerns between a data container's actual payload information and the type information of that container's payload. In this sense, type information is metadata, not data. The Schema dialect used by ACDCs is JSON Schema 2020-12 [[10]] [[11]]. JSON Schema supports composable schema (subschema), conditional Schema (subschema), and regular expressions in the Schema. Composability enables a Validator to ask and answer complex questions about the type of even optional payload elements while maintaining isolation between payload information and type (structure) information about the payload [[39]] [[40]] [[41]] [[42]]. A static but composed schema allows a verifiably immutable set of variants. Although the set is immutable, the variants enable graduated but secure disclosure. ACDC's use of JSON Schema must be in accordance with the ACDC defined profile as defined herein. The exceptions are defined below.
+Notable is the fact that no top-level type fields exist in an ACDC. This is because the [[ref: Schema]], `s`, field itself is the type field for the ACDC and its parts. ACDCs follow the design principle of separation of concerns between a data container's actual payload information and the type information of that container's payload. In this sense, type information is metadata, not data. The Schema dialect used by ACDCs is JSON Schema 2020-12 [[10]] [[11]]. JSON Schema supports composable schema (subschema), conditional Schema (subschema), and regular expressions in the Schema. Composability enables a Validator to ask and answer complex questions about the type of even optional payload elements while maintaining isolation between payload information and type (structure) information about the payload [[39]] [[40]] [[41]] [[42]]. A static but composed schema allows a verifiably immutable set of variants. Although the set is immutable, the variants enable graduated but secure disclosure. ACDC's use of JSON Schema MUST be in accordance with the ACDC defined profile as defined herein. The exceptions are defined below.
 
 #### Schema ID field label
 
-The usual field label for SAID fields in ACDCs is `d`. In the case of the [[ref: Schema]] section, however, the field label for the SAID of the Schema section is `$id`. This repurposes the Schema id field label, `$id` as defined by JSON Schema [[41]] [[42]].  The top-level id, `$id`, field value in a JSON Schema provides a unique identifier of the Schema instance. In a non-ACDC schema, the value of the id, `$id`, field is expressed as a URI. This is called the Base URI of the schema. In an ACDC schema, however, the top-level id, `$id`, field value is repurposed. This field value must include the SAID of the schema. This ensures that the ACDC Schema is static and verifiable to their SAIDs. A verifiably static Schema satisfies one of the essential security properties of ACDCs as discussed below. There are several ACDC supported formats for the value of the top-level id, `$id`, field but all of the formats must include the SAID of the Schema (see below). Correspondingly, the value of the top-level schema, `s`, field must be the SAID included in the schema's top-level `$id` field. The detailed schema is either attached or cached and maybe discovered via its SAIDified id, `$id`, field value.
+The usual field label for SAID fields in ACDCs is `d`. In the case of the [[ref: Schema]] section, however, the field label for the SAID of the Schema section is `$id`. This repurposes the Schema id field label, `$id` as defined by JSON Schema [[41]] [[42]].  The top-level id, `$id`, field value in a JSON Schema provides a unique identifier of the Schema instance. In a non-ACDC schema, the value of the id, `$id`, field is expressed as a URI. This is called the Base URI of the schema. In an ACDC schema, however, the top-level id, `$id`, field value is repurposed. This field value MUST include the SAID of the schema. This ensures that the ACDC Schema is static and verifiable to their SAIDs. A verifiably static Schema satisfies one of the essential security properties of ACDCs as discussed below. There are several ACDC supported formats for the value of the top-level id, `$id`, field but all of the formats MUST include the SAID of the Schema (see below). Correspondingly, the value of the top-level schema, `s`, field MUST be the SAID included in the schema's top-level `$id` field. The detailed schema is either attached or cached and maybe discovered via its SAIDified id, `$id`, field value.
 
-The digest algorithm employed for generating [[ref: Schema]] SAIDs shall have an approximate cryptographic strength of 128 bits. The [[3]] MUST be generated in compliance with the ToIP SAID internet draft specification and MUST be encoded using CESR. The CESR encoding indicates the type of cryptographic digest used to generate the SAID. 
+The digest algorithm employed for generating [[ref: Schema]] SAIDs MUST have an approximate cryptographic strength of 128 bits. The [[3]] MUST be generated in compliance with the ToIP SAID internet draft specification and MUST be encoded using CESR. The CESR encoding indicates the type of cryptographic digest used to generate the SAID. 
 
-When an id, `$id`, field appears in a subschema, it indicates a bundled subschema called a schema resource [[41]] [[42]]. The value of the id, `$id`, field in any ACDC bundled subschema resource must include the SAID of that subschema using one of the formats described below. The subschema so bundled must be verifiable against its referenced and embedded SAID value. This ensures secure bundling.
+When an id, `$id`, field appears in a subschema, it indicates a bundled subschema called a schema resource [[41]] [[42]]. The value of the id, `$id`, field in any ACDC bundled subschema resource MUST include the SAID of that subschema using one of the formats described below. The subschema so bundled MUST be verifiable against its referenced and embedded SAID value. This ensures secure bundling.
 
 #### Static (immutable) schema
 
-For security reasons, the full Schema of an ACDC must be completely self-contained and statically fixed (immutable) for that ACDC meaning that no dynamic Schema references or dynamic Schema generation mechanisms are allowed.
+For security reasons, the full Schema of an ACDC MUST be completely self-contained and statically fixed (immutable) for that ACDC meaning that no dynamic Schema references or dynamic Schema generation mechanisms are allowed.
 
 Should an adversary successfully attack the source that provides the dynamic Schema resource and change the result provided by that reference, then the Schema validation on any ACDC that uses that dynamic Schema reference may fail. Such an attack effectively revokes all the ACDCs that use that dynamic Schema reference, which is called a Schema revocation attack.
 
 More insidiously, an attacker could shift the semantics of the dynamic Schema in such a way that although the ACDC still passes its Schema validation, the behavior of the downstream processing of that ACDC is changed by the semantic shift. This type of attack is called a semantic malleability attack which may be considered a new type of transaction malleability attack [[55]].
 
-To prevent both forms of attack, all Schema must be static, i.e., Schema must be SADs and therefore verifiable against their SAIDs.
+To prevent both forms of attack, all Schema MUST be static, i.e., Schema MUST be SADs and therefore verifiable against their SAIDs.
 
-To elaborate, the serialization of a static schema may be self-contained. A compact commitment to the detailed static Schema may be provided by its SAID. In other words, the SAID of a static Schema is a verifiable cryptographic identifier for its SAD. Therefore, all ACDC compliant Schema must be SADs. In other words, the Schema must therefore be SAIDified. The associated detailed static Schema (uncompacted SAD) is bound cryptographically and verifiable to its SAID.
+To elaborate, the serialization of a static schema SHOULD be self-contained. A compact commitment to the detailed static Schema is provided by its SAID. In other words, the SAID of a static Schema is a verifiable cryptographic identifier for its SAD. Therefore, all ACDC compliant Schema MUST be SADs. In other words, the Schema MUST therefore be SAIDified. The associated detailed static Schema (uncompacted SAD) is bound cryptographically and verifiable to its SAID.
 
-The JSON Schema specification allows complex Schema references that may include non-local URI references [[41]] [[42]] [[15]] [[16]]. These references may use the `$id` or `$ref` keywords. A relative URI reference provided by a `$ref` keyword is resolved against the Base URI provided by the top-level `$id` field. When this top-level Base URI is non-local, then all relative `$ref` references are therefore also non-local. A non-local URI reference provided by a `$ref` keyword may be resolved without reference to the Base URI.
+The JSON Schema specification allows complex Schema references that MAY include non-local URI references [[41]] [[42]] [[15]] [[16]]. These references may use the `$id` or `$ref` keywords. A relative URI reference provided by a `$ref` keyword is resolved against the Base URI provided by the top-level `$id` field. When this top-level Base URI is non-local, then all relative `$ref` references are, therefore, also non-local. A non-local URI reference provided by a `$ref` keyword may be resolved without reference to the Base URI.
 
-In general, Schema indicated by non-local URI references (`$id` or `$ref`) must not be used because they are not cryptographically end-verifiable. The value of the underlying Schema resource so referenced may change (mutate). To restate, a non-local URI Schema resource is not end-verifiable to its URI reference because there is no cryptographic binding between URI and resource [[15]] [[16]].
+In general, Schema indicated by non-local URI references (`$id` or `$ref`) MUST not be used because they are not cryptographically end-verifiable. The value of the underlying Schema resource so referenced MAY change (mutate). To restate, a non-local URI Schema resource is not end-verifiable to its URI reference because there is no cryptographic binding between URI and resource [[15]] [[16]].
 
-This does not preclude the use of remotely cached SAIDified Schema resources because those resources are end-verifiable to their embedded SAID references. Said another way, a SAIDified Schema resource is itself a SAD referenced by its SAID. A URI that includes a SAID may be used to securely reference a remote or distributed SAIDified schema resource because that resource is fixed (immutable, nonmalleable) and verifiable to both the SAID in the reference and the embedded SAID in the resource so referenced. To elaborate, a non-local URI reference that includes an embedded cryptographic commitment such as a SAID is verifiable to the underlying resource when that resource is a SAD. This applies to JSON Schema as a whole as well as bundled subschema resources.
+This does not preclude the use of remotely cached SAIDified Schema resources because those resources are end-verifiable to their embedded SAID references. Said another way, a SAIDified Schema resource is itself a SAD referenced by its SAID. A URI that includes a SAID MAY be used to securely reference a remote or distributed SAIDified schema resource because that resource is fixed (immutable, nonmalleable) and verifiable to both the SAID in the reference and the embedded SAID in the resource so referenced. To elaborate, a non-local URI reference that includes an embedded cryptographic commitment such as a SAID is verifiable to the underlying resource when that resource is a SAD. This applies to JSON Schema as a whole as well as bundled subschema resources.
 
-The ACDC supported formats for the value of the top-level id, `$id`, field are as follows:
+The REQUIRED ACDC supported formats for the value of the top-level id, `$id`, field are as follows:
 
-Bare SAIDs may be used to refer to a SAIDified Schema as long as the JSON Schema validator supports bare SAID references. By default, many if not all JSON Schema Validators support bare strings (non-URIs) for the Base URI provided by the top-level `$id` field value.
+Bare SAIDs MAY be used to refer to a SAIDified Schema as long as the JSON Schema validator supports bare SAID references. By default, many if not all JSON Schema Validators support bare strings (non-URIs) for the Base URI provided by the top-level `$id` field value.
 
--	The `sad:` URI scheme may be used to directly indicate a URI resource that safely returns a verifiable SAD. For example, `sad:SAID` where SAID is replaced with the actual SAID of a SAD that provides a verifiable non-local reference to JSON Schema as indicated by the media-type of `schema+json`.
+-	The `sad:` URI scheme MAY be used to directly indicate a URI resource that safely returns a verifiable SAD. For example, `sad:SAID` where SAID is replaced with the actual SAID of a SAD that provides a verifiable non-local reference to JSON Schema as indicated by the media-type of `schema+json`.
 
--	The KERI OOBI specification provides a URL syntax that references a SAD resource by its SAID at the service endpoint indicated by that URL [[4]]. Such remote OOBI URLs are also safe because the provided SAD resource is verifiable against the SAID in the OOBI URL. Therefore, OOBI URLs are also acceptable non-local URI references for JSON Schema [[4]] [[15]] [[16]].
+-	The KERI OOBI specification provides a URL syntax that references a SAD resource by its SAID at the service endpoint indicated by that URL [[4]]. Such remote OOBI URLs are also safe because the provided SAD resource is verifiable against the SAID in the OOBI URL. Therefore, OOBI URLs MAY be used as non-local URI references for JSON Schema [[4]] [[15]] [[16]].
 
--	The `did:` URI scheme may be used safely to prefix non-local URI references that act to namespace SAIDs expressed as DID URIs or DID URLs.  DID resolvers resolve DID URLs for a given DID method such as `did:keri` [[5]] and may return DID docs or DID doc metadata with SAIDified schema or service endpoints that return SAIDified schema or OOBIs that return SAIDified schema [[15]] [[16]] [[4]]. A verifiable non-local reference in the form of DID URL that includes the schema SAID is resolved safely when it dereferences to the SAD of that SAID. For example, the resolution result returns an ACDC JSON Schema whose id, `$id`, field includes the SAID and returns a resource with JSON Schema mime-type of `schema+json`.
+-	The `did:` URI scheme MAY be used safely to prefix non-local URI references that act to namespace SAIDs expressed as DID URIs or DID URLs.  DID resolvers resolve DID URLs for a given DID method such as `did:keri` [[5]] and may return DID docs or DID doc metadata with SAIDified schema or service endpoints that return SAIDified schema or OOBIs that return SAIDified schema [[15]] [[16]] [[4]]. A verifiable non-local reference in the form of DID URL that includes the schema SAID is resolved safely when it dereferences to the SAD of that SAID. For example, the resolution result returns an ACDC JSON Schema whose id, `$id`, field includes the SAID and returns a resource with JSON Schema mime-type of `schema+json`.
 
-To clarify, ACDCs must not use complex JSON Schema references which allow dynamically generated Schema resources to be obtained from online JSON Schema Libraries [[41]] [[42]]. The latter approach may be difficult or impossible to secure because a cryptographic commitment to the base Schema that includes complex Schema (non-relative URI-based) references only commits to the non-relative URI reference and not to the actual schema resource which may change (is dynamic, mutable, malleable). To restate, this approach is insecure because a cryptographic commitment to a complex (non-relative URI-based) reference is not equivalent to a commitment to the detailed associated Schema resource so referenced if it may change.
+To clarify, ACDCs MUST NOT use complex JSON Schema references which allow dynamically generated Schema resources to be obtained from online JSON Schema Libraries [[41]] [[42]]. The latter approach may be difficult or impossible to secure because a cryptographic commitment to the base Schema that includes complex Schema (non-relative URI-based) references only commits to the non-relative URI reference and not to the actual schema resource which may change (is dynamic, mutable, malleable). To restate, this approach is insecure because a cryptographic commitment to a complex (non-relative URI-based) reference is not equivalent to a commitment to the detailed associated Schema resource so referenced if it may change.
 
-ACDCs must use static JSON Schema (i.e., SAIDifiable Schema). These may include internal relative references to other parts of a fully self-contained static (SAIDified) Schema or references to static (SAIDified) external Schema parts. As indicated above, these references may be bare SAIDs, DID URIs or URLs (`did:` scheme), SAD URIs (`sad:` scheme), or OOBI URLs [[4]]. Recall that a commitment to a SAID with sufficient collision resistance makes an equivalent secure commitment to its encapsulating block SAD. Thus, static schema may be either fully self-contained or distributed in parts but the value of any reference to a part must be verifiably static (immutable, nonmalleable) by virtue of either being relative to the self-contained whole or being referenced by its SAID. The static schema in whole or in parts may be attached to the ACDC itself or provided via a highly available cache or data store. To restate, this approach is securely end-verifiable (zero-trust) because a cryptographic commitment to the SAID of a SAIDified schema is equivalent to a commitment to the detailed associated schema itself (SAD).
+ACDCs MUST use static JSON Schema (i.e., SAIDifiable Schema). These MAY include internal relative references to other parts of a fully self-contained static (SAIDified) Schema or references to static (SAIDified) external Schema parts. As indicated above, these references MAY be bare SAIDs, DID URIs or URLs (`did:` scheme), SAD URIs (`sad:` scheme), or OOBI URLs [[4]]. Recall that a commitment to a SAID with sufficient collision resistance makes an equivalent secure commitment to its encapsulating block SAD. Thus, static schema MAY be either fully self-contained or distributed in parts but the value of any reference to a part MUST be verifiably static (immutable, nonmalleable) by virtue of either being relative to the self-contained whole or being referenced by its SAID. The static schema in whole or in parts MAY be attached to the ACDC itself or provided via a highly available cache or data store. To restate, this approach is securely end-verifiable (zero-trust) because a cryptographic commitment to the SAID of a SAIDified schema is equivalent to a commitment to the detailed associated schema itself (SAD).
 
 #### Schema dialect
 
-The Schema dialect for ACDC 1.0 is JSON Schema 2020-12 and is indicated by the identifier `"https://json-schema.org/draft/2020-12/schema"`  [[10]] [[11]]. This is indicated in a JSON Schema via the value of the top-level `$schema` field. Although the value of `$schema` is expressed as a URI, de-referencing does not provide dynamically downloadable schema dialect validation code. This would be an attack vector. The Validator must control the tooling code dialect used for Schema validation and hence the tooling dialect version actually used. A mismatch between the supported tooling code dialect version and the `$schema` string value should cause the validation to fail. The string is simply an identifier that communicates the intended dialect to be processed by the Schema validation tool. When provided, the top-level `$schema` field value for ACDC version 1.0 must be "https://json-schema.org/draft/2020-12/schema".
+The Schema dialect for ACDC 1.0 MUST be JSON Schema 2020-12 and is indicated by the identifier `"https://json-schema.org/draft/2020-12/schema"`  [[10]] [[11]]. This is indicated in a JSON Schema via the value of the top-level `$schema` field. Although the value of `$schema` is expressed as a URI, de-referencing does not provide a dynamically downloadable schema dialect validation code. This would be an attack vector. The Validator MUST control the tooling code dialect used for Schema validation and hence the tooling dialect version actually used. A mismatch between the supported tooling code dialect version and the `$schema` string value SHOULD cause the validation to fail. The string MUST be treated simply as an identifier that communicates the intended dialect to be processed by the Schema validation tool. When provided, the top-level `$schema` field value for ACDC version 1.0 MUST be "https://json-schema.org/draft/2020-12/schema".
 
 #### Schema versioning
 
-Each schema shall have at the top level version field with field label `version`. The value of the `version` field shall be a semantic version string in the dotted decimal notation of the form "major.minor.patch" . For example, "1.2.3" has a major version number of 1, a minor version number of 2, and a patch version of 3. This value is informative. The `version` field value is not used in the JSON Schema validation against the ACDC. Therefore, a given ACDC may properly pass JSON Schema validation process regardless of the value of its schema `version` field. [[ref: SEMVER]]
+Each schema MUST have at the top level version field with field label `version`. The value of the `version` field MUST be a semantic version string in the dotted decimal notation of the form "major.minor.patch" . For example, "1.2.3" has a major version number of 1, a minor version number of 2, and a patch version of 3. This value is informative. The `version` field value is not used in the JSON Schema validation against the ACDC. Therefore, a given ACDC SHOULD properly pass JSON Schema validation process regardless of the value of its schema `version` field. [[ref: SEMVER]]
 
-Recall that the value of the Schema ID, `$id` field in an ACDC Schema is a SAID which provides an encoded agile cryptographic digest of the contents of the schema. Any change to the schema, including a change to its `version` field, results in a new SAID. Any copy of a schema that verifies against the same SAID given by the Schema ID, `$id` field value can be assumed to be identical to any other copy that verifies to the same SAID by virtue of the strong collision resistance of the digest employed.
+Recall that the value of the Schema ID, `$id` field in an ACDC Schema is a SAID that provides an encoded agile cryptographic digest of the contents of the schema. Any change to the schema, including a change to its `version` field, results in a new SAID. Any copy of a schema that verifies against the same SAID given by the Schema ID, `$id` field value SHOULD be assumed to be identical to any other copy that verifies to the same SAID by virtue of the strong collision resistance of the digest employed.
 
-This gives rise to two meanings of the word "version" when applied to an ACDC's Schema. One is the version given by the value of its `$id` field, and the other is the version given by its `version` field. The version provided by the `$id` field is cryptographically verifiable. Whereas the version provided by the `version` field is not. Thus, the latter is an informative indication of the version, and the former is a normative determiner of the version. In this sense, the Schema ID, `$id` field value as a SAID provides a cryptographically verifiable version indicator independent of the version field value. To avoid confusion, any change to the Schema that changes the value of the `$id` shall also be reflected in a correspondingly unique value of its `version` field. Business logic may depend on consistency between the `version` field value with respect to the `$id` field value. Notwithstanding the actual value of the `version` field, the `$id` field value is the normative determiner of the Schema's true, verifiable version.
+This gives rise to two meanings of the word "version" when applied to an ACDC's Schema. One is the version given by the value of its `$id` field, and the other is the version given by its `version` field. The version provided by the `$id` field is cryptographically verifiable. Whereas the version provided by the `version` field is not. Thus, the latter is an informative indication of the version, and the former is a normative determiner of the version. In this sense, the Schema ID, `$id` field value as a SAID provides a cryptographically verifiable version indicator independent of the version field value. To avoid confusion, any change to the Schema that changes the value of the `$id` MUST also be reflected in a correspondingly unique value of its `version` field. Business logic may depend on consistency between the `version` field value with respect to the `$id` field value. Notwithstanding the actual value of the `version` field, the `$id` field value is the normative determiner of the Schema's true, verifiable version.
 
-The JSON Schema for an ACDC may use composition operators (see below). This allows extensibility in schema such that, in some cases, ACDCs with newer Schema versions may be backward (in)compatible with older schema versions. A new schema version, as given by the `$id` field value, is considered backward incompatible with respect to a previous version of a Schema when any instance of an ACDC that validates (in the JSON Schema sense of validation) against the previous version of the Schema may not be guaranteed to validate against the new version. Because any change to the `version` field value results in a different `$id` field value, the backward compatibility rule also applies changes in the `version` field value. To comply with the semantic versioning rules, a backward incompatible Schema shall have a higher major version number in its `version` field value than any backward incompatible version.
+The JSON Schema for an ACDC MAY use composition operators (see below). This allows extensibility in schema such that, in some cases, ACDCs with newer Schema versions may be backward (in)compatible with older schema versions. A new schema version, as given by the `$id` field value, is considered backward incompatible with respect to a previous version of a Schema when any instance of an ACDC that validates (in the JSON Schema sense of validation) against the previous version of the Schema may not be guaranteed to validate against the new version. Because any change to the `version` field value results in a different `$id` field value, the backward compatibility rule also applies changes in the `version` field value. To comply with the semantic versioning rules, a backward incompatible Schema MUST have a higher major version number in its `version` field value than any backward incompatible version.
 
-One complication with schema versioning arises when an ACDC has Edges. As discussed below in the Edge section, an Edge block may have a Schema, `s` field, which indicates that the ACDC node the edge points to must validate against the schema indicated by the Edge's Schema, `s` field value. Consequently, the version of the Edge's schema `s` field value may differ from the version of the Schema `s` field value in the ACDC node pointed to by that edge. If both schemas validate, then the Edge's schema version is backward compatible with the ACDC's schema version (node pointed to by the Edge). This means the Edge's schema version may have a higher minor version number than the ACDC's schema version (node pointed to by the Edge). If the Edge's schema does not validate against the ACDC node pointed to by the edge, then the Edge's schema is backward incompatible and shall have a higher major version number than the ACDC's schema (node pointed to by the edge).  In this latter case, ACDCs issued under the old major version must either be revoked and reissued to comply with the new major version schema, or the Edge's schema must include a `oneOf` composition that accepts either old or new major versions. In general, this would lead to extending that list of `oneOf`s in that Edge's schema field value to include an entry for each major version change.
+One complication with schema versioning arises when an ACDC has Edges. As discussed below in the Edge section, an Edge block MAY have a Schema, `s` field, which indicates that the ACDC node the edge points to MUST validate against the schema indicated by the Edge's Schema, `s` field value. Consequently, the version of the Edge's schema `s` field value MAY differ from the version of the Schema `s` field value in the ACDC node pointed to by that edge. If both schemas validate, then the Edge's schema version is backward compatible with the ACDC's schema version (node pointed to by the Edge). This means the Edge's schema version MAY have a higher minor version number than the ACDC's schema version (node pointed to by the Edge). If the Edge's schema does not validate against the ACDC node pointed to by the edge, then the Edge's schema is backward incompatible and MUST have a higher major version number than the ACDC's schema (node pointed to by the edge).  In this latter case, ACDCs issued under the old major version MUST either be revoked and reissued to comply with the new major version schema, or the Edge's schema MUST include a `oneOf` composition that accepts either old or new major versions. In general, this would lead to extending that list of `oneOf`s in that Edge's schema field value to include an entry for each major version change.
 
 #### Schema availability
 
-The composed detailed (uncompacted) (bundled) static Schema for an ACDC may be cached or attached. But cached, and/or attached static Schema is not to be confused with dynamic Schema. Nonetheless, while securely verifiable, a remotely cached, SAIDified, Schema resource may be unavailable. Availability is a separate concern. Unavailable does not mean insecure or unverifiable. ACDCs must be verifiable when available.  Availability is typically solvable through redundancy. Although a given ACDC application domain or ecosystem governance framework (EGF) may impose schema availability constraints, this ACDC specification itself does not impose any specific availability requirements on Issuers other than schema caches should be sufficiently available for the intended application of their associated ACDCs. It is up to the Issuer of an ACDC to satisfy any availability constraints on its Schema that may be imposed by the application domain or ecosystem.
+The composed detailed (uncompacted) (bundled) static Schema for an ACDC MAY be cached or attached. But cached, and/or attached static Schema is not to be confused with dynamic Schema. Nonetheless, while securely verifiable, a remotely cached, SAIDified, Schema resource may be unavailable. Availability is a separate concern. Unavailable does not mean insecure or unverifiable. ACDCs MUST be verifiable when available.  Availability is typically solvable through redundancy. Although a given ACDC application domain or ecosystem governance framework (EGF) may impose schema availability constraints, this ACDC specification itself does not impose any specific availability requirements on Issuers other than schema caches SHOULD be sufficiently available for the intended application of their associated ACDCs. The Issuer of an ACDC is REQUIRED to satisfy any availability constraints on its Schema that MAY be imposed by the application domain or ecosystem.
 
 #### Composable JSON Schema
 
-A composable JSON Schema enables the use of any combination of compacted/uncompacted Attribute, Edge, and Rule sections in a provided ACDC. When compact, any one of these sections may be represented merely by its SAID [[10]] [[39]]. When used for the top-level attribute, `a`, edge, `e`, or rule, `r`, section field values, the `oneOf` subschema composition operator provides both compact and uncompacted variants. The provided ACDC must validate against an allowed combination of the composed variants. The Validator determines what decomposed variants the provided ACDC must also validate against. Decomposed variants may be dependent on the type of Graduated Disclosure. Essentially, a composable schema is a verifiable bundle of metadata (composed) about content that can then be verifiably unbundled (decomposed) later. The Issuer makes a single verifiable commitment to the bundle (composed Schema), and a recipient may then safely unbundle (decompose) the schema to validate any of the Graduated disclosure variants allowed by the composition.
+A composable JSON Schema enables the use of any combination of compacted/uncompacted Attribute, Edge, and Rule sections in a provided ACDC. When compact, any one of these sections MAY be represented merely by its SAID [[10]] [[39]]. When used for the top-level attribute, `a`, edge, `e`, or rule, `r`, section field values, the `oneOf` subschema composition operator provides both compact and uncompacted variants. The provided ACDC MUST validate against an allowed combination of the composed variants. The Validator determines what decomposed variants the provided ACDC MUST also validate against. Decomposed variants MAY be dependent on the type of Graduated Disclosure. Essentially, a composable schema is a verifiable bundle of metadata (composed) about content that can then be verifiably unbundled (decomposed) later. The Issuer makes a single verifiable commitment to the bundle (composed Schema), and a recipient may then safely unbundle (decompose) the schema to validate any of the Graduated disclosure variants allowed by the composition.
 
-Unlike the other compactifiable sections, it is impossible to define recursively the exact detailed schema as a variant of a `oneOf` composition operator contained in itself.  Nonetheless, the provided schema, whether self-contained, attached, or cached must validate as a SAD against its provided SAID. It also must validate against one of its specified `oneOf` variants. Typically, it's SAID or a generic object.
+Unlike the other compactifiable sections, it is impossible to define recursively the exact detailed schema as a variant of a `oneOf` composition operator contained in itself.  Nonetheless, the provided schema, whether self-contained, attached, or cached MUST validate as a SAD against its provided SAID. It also MUST validate against one of its specified `oneOf` variants. Typically, it's SAID or a generic object.
 
-The compliance of the provided non-schema attribute, `a`, edge, `e`, and rule, `r`, sections must be enforced by validating against the composed Schema. In contrast, the compliance of the provided composed schema for an expected ACDC type must be enforced by the Validator. This is because it is not possible to enforce strict compliance of the schema by validating it against itself.
+The compliance of the provided non-schema attribute, `a`, edge, `e`, and rule, `r`, sections MUST be enforced by validating against the composed Schema. In contrast, the compliance of the provided composed schema for an expected ACDC type SHOULD be enforced by the Validator. This is because it is not possible to enforce strict compliance of the schema by validating it against itself.
 
 ACDC-specific Schema compliance requirements usually are specified in the EGF for a given ACDC type.  Because the SAID of a Schema is a unique content-addressable identifier of the Schema itself, compliance can be enforced by comparison to the allowed schema SAID in a well-known publication or registry of ACDC types for a EGF. The EGF may be specified solely by the Issuer for the ACDCs it generates or be specified by some mutually agreed upon ecosystem governance mechanism. Typically, the business logic for making a decision about a presentation of an ACDC starts by specifying the SAID of the composed Schema for the ACDC type that the business logic is expecting from the presentation. The verified SAID of the actually presented Schema is then compared against the expected SAID. If they match, then the actually presented ACDC may be validated against any desired decomposition of the expected (composed) Schema.
 
@@ -733,7 +740,7 @@ The following field labels are reserved at all nested field map levels in the At
 |`dt`| Datetime | Issuer's relative ISO datetime string |
 
 ##### Datetime, `dt` field
-The datetime, `dt` field value, if any, shall be the ISO-8601 datetime string with microseconds and UTC offset as per IETF RFC-3339. This datetime is relative to the clock of the issuer. Attributes typically include one or more date time fields. In a given field map (block) the primary datetime will use the label, `dt`. Typically, this is the datetime of the issuance of the ACDC. Other datetime fields may include an expiration datetime or the like.
+The datetime, `dt` field value, if any, MUST be the ISO-8601 datetime string with microseconds and UTC offset as per IETF RFC-3339. This datetime is relative to the clock of the issuer. Attributes typically include one or more date time fields. In a given field map (block) the primary datetime will use the label, `dt`. Typically, this is the datetime of the issuance of the ACDC. Other datetime fields MAY include an expiration datetime or the like.
 
  An example datetime string in this format is as follows:
 
@@ -762,7 +769,7 @@ Two variants, namely, Targeted (Untargeted), are defined respectively by the pre
 
 Two other variants, namely private (public), are defined respectively by the presence (absence) of a UUID, `u`, field at the top-level of the uncompacted Attribute section block.
 
-These four variants may appear in combination.
+These four variants MAY appear in combination.
 
 ##### Targeted attribute section 
 
@@ -781,17 +788,19 @@ Consider the case where the Issuee, `i`, field is present at the top level of th
 }
 ```
 
-When present at the top level of the Attribute section, the Issuee, `i`, field value is the ACDC's Issuee AID. This Issuee AID is a provably controllable identifier that is the Target. This makes the ACDC a Targeted ACDC. Targeted ACDCs may be used for many different purposes, such as authorization or delegation directed at the Target. In other words, a targeted ACDC provides a container for authentic data that may also be used as some form of authorization, such as a credential that is verifiably bound to the Issuee as targeted by the Issuer. Furthermore, by virtue of the targeted Issuee's provable control over its AID, the Targeted ACDC may be verifiably presented (disclosed) by the Issuee AID Controller.
+When present at the top level of the Attribute section, the Issuee, `i`, field value is the ACDC's Issuee AID. This Issuee AID is a provably controllable identifier that is the Target. This makes the ACDC a Targeted ACDC. Targeted ACDCs MAY be used for many different purposes, such as authorization or delegation directed at the Target. In other words, a targeted ACDC provides a container for authentic data that MAY also be used as some form of authorization, such as a credential that is verifiably bound to the Issuee as targeted by the Issuer. Furthermore, by virtue of the targeted Issuee's provable control over its AID, the Targeted ACDC MAY be verifiably presented (disclosed) by the Issuee AID Controller.
 
 To elaborate, the definition of the term credential is "evidence of authority, status, rights, entitlement to privileges, or the like". The presence of an attribute section top-level Issuee, `i`, field enables the ACDC to be used as a Verifiable Credential given by the Issuer to the Issuee.
 
-One reason the Issuee, `i`, field is nested into the Attribute section, `a`, block is to enable the Issuee AID to be partially or selectively disclosable. Because the actual semantics of Issuee may depend on the use case, the semantically precise albeit less common terms of Issuer and Issuee are used in this specification. In some use cases, for example, an Issuee may be called the Holder; in others, the Subject of the ACDC. But no matter the use case, the `i` field designates the Issuee AID, i.e. Target. The ACDC is "issued by" an Issuer and is "issued to" an Issuee. This precise terminology does not bias or color the role (function) that an Issuee plays in using an ACDC. What the presence of Issuee AID does provide is a mechanism for control of the subsequent use of the ACDC once it has been issued. To elaborate, because the Issuee, `i`, field value is an AID, by definition, there is a provable Controller of that AID. Therefore, the Issuee Controller may make non-repudiable commitments via digital signatures on behalf of its AID.  Therefore, subsequent use of the ACDC by the Issuee may be securely attributed to the Issuee.
+One reason the Issuee, `i`, field is nested into the Attribute section, `a`, block is to enable the Issuee AID to be partially or selectively disclosable. Because the actual semantics of Issuee may depend on the use case, the semantically precise albeit less common terms of Issuer and Issuee are used in this specification. In some use cases, for example, an Issuee may be called the Holder; in others, the Subject of the ACDC. But no matter the use case, the `i` field designates the Issuee AID, i.e. Target. The Issuee MUST be designated by the `i` field at the top-level of the attribute, `a` or `A` aggregate field block. 
 
-Importantly, the presence of an Issuee, `i`, field enables the associated Issuee to make authoritative verifiable presentations or disclosures of the ACDC. A designated Issuee also better enables the initiation of presentation exchanges of the ACDC between that Issuee as Discloser and a Disclosee (Verifier).
+The ACDC MUST be "issued by" an Issuer and MUST be "issued to" an Issuee. This precise terminology does not bias or color the role (function) an Issuee plays in using an ACDC. What the presence of Issuee AID does provide is a mechanism for control of the subsequent use of the ACDC once it has been issued. To elaborate, because the Issuee, `i`, field value MUST be an AID, by definition, there is a provable Controller of that AID. Therefore, the Issuee Controller MAY make non-repudiable commitments via digital signatures on behalf of its AID.  Therefore, subsequent use of the ACDC by the Issuee MAY be securely attributed to the Issuee.
 
-In addition, because the Issuee is a specified counterparty, the Issuer may engage in a contract with the Issuee that the Issuee agrees to by virtue of its non-repudiable signature on an offer of the ACDC prior to its issuance. This agreement may be a pre-condition to the issuance and thereby impose liability waivers or other terms of use on that Issuee. 
+Importantly, the presence of an Issuee, `i`, field means that the associated Issuee MAY make authoritative verifiable presentations or disclosures of the ACDC. A designated Issuee also better enables the initiation of presentation exchanges of the ACDC between that Issuee as Discloser and a Disclosee (Verifier).
 
-Likewise, the presence of an Issuee, `i`, field enables the Issuer to use the ACDC as a contractual vehicle for conveying authorization to the Issuee.  This enables verifiable delegation chains of authority because the Issuee in one ACDC may become the Issuer of another ACDC. Thereby, an Issuer may delegate authority to an Issuee who may then become a verifiably authorized Issuer that then delegates that authority (or attenuation of that authority) to some other verifiably authorized Issuee and so forth.
+In addition, because the Issuee is a specified counterparty, the Issuer MAY engage in a contract with the Issuee that the Issuee agrees to by virtue of its non-repudiable signature on an offer of the ACDC prior to its issuance. This agreement MAY be a pre-condition to the issuance and thereby MAY impose liability waivers or other terms of use on that Issuee. 
+
+Likewise, the presence of an Issuee, `i`, field means that the Issuer MAY use the ACDC as a contractual vehicle for conveying authorization to the Issuee.  This enables verifiable delegation chains of authority because the Issuee in one ACDC may become the Issuer of another ACDC. Thereby, an Issuer MAY delegate authority to an Issuee who MAY then become a verifiably authorized Issuer who in turn MAY delegate that authority (or attenuation of that authority) to some other verifiably authorized Issuee and so forth.
 
 Contractual issuance and presentation exchanges are described in detail later in the IPEX protocol section {{reference to IPEX section}}.
 
@@ -814,9 +823,9 @@ Consider the case where the Issuee, `i`, field is absent at the top level of the
 }
 ```
 
-This ACDC has an Issuer but no Issuee. There is no provably controllable AID as a Target of the issuance, i.e., Untargeted. The data in the Attribute section may be considered an undirected verifiable attestation or observation by the Issuer.  The attestation is addressed "to whom it may concern." An Untargeted ACDC enables verifiable authorship by the Issuer of the data in the Attributes section, but there is no specified counterparty and no verifiable mechanism for delegation of authority.  Consequently, the Rules section may provide only contractual obligations of implied counterparties.
+This ACDC has an Issuer but no Issuee. There is no provably controllable AID as a Target of the issuance, i.e., Untargeted. The data in the Attribute section MAY be considered an undirected verifiable attestation or observation by the Issuer.  The attestation is addressed "to whom it may concern." An Untargeted ACDC enables verifiable authorship by the Issuer of the data in the Attributes section, but there is no specified counterparty and no verifiable mechanism for delegation of authority.  Consequently, the Rules section MAY provide only contractual obligations of implied counterparties.
 
-This form of an ACDC provides a container for authentic data only (not authentic data as authorization). But authentic data is still a very important use case. To clarify, an Untargeted ACDC enables verifiable authorship of data. An observer, such as a sensor that controls an AID, may make verifiable, nonrepudiable measurements and publish them as ACDCs. These may be chained together to provide provenance for or a chain-of-custody of any data.  Furthermore, a hybrid chain of one or more targeted ACDCs ending in a chain of one or more Untargeted ACDCs enables delegated authorized attestations at the tail of that chain. These provenanceable chains of ACDCs could be used to provide a verifiable data supply chain for any compliance-regulated application. This provides a way to protect participants in a supply chain from imposters. Such data supply chains are also useful as a verifiable digital twin of a physical supply chain [[54]].
+This form of an ACDC provides a container for authentic data only (not authentic data as authorization). But authentic data is still a very important use case. To clarify, an Untargeted ACDC enables verifiable authorship of data. An observer, such as a sensor that controls an AID, MAY make verifiable, nonrepudiable measurements and publish them as ACDCs. These MAY be chained together to provide provenance for or a chain-of-custody of any data.  Furthermore, a hybrid chain of one or more targeted ACDCs ending in a chain of one or more Untargeted ACDCs enables delegated authorized attestations at the tail of that chain. These provenanceable chains of ACDCs could be used to provide a verifiable data supply chain for any compliance-regulated application. This provides a way to protect participants in a supply chain from imposters. Such data supply chains are also useful as a verifiable digital twin of a physical supply chain [[54]].
 
 
 #### Targeted private-attribute section example
@@ -899,11 +908,11 @@ with subschema below,
 
 As described above in the Schema section of this specification, the `oneOf` subschema composition operator validates against either the compact SAID of a block or the full block. A Validator can use a composed Schema that has been committed to by the Issuer to securely confirm Schema compliance both before and after detailed disclosure by using the fully composed base Schema pre-disclosure and a specific decomposed variant post-disclosure. Decomposing the Schema to remove the optional compact variant (i.e., removing the `oneOf` compact option) enables a Validator to ensure compliant Full Disclosure. To clarify, using the JSON Schema `oneOf` composition Operator enables the composed subschema to validate against both the compact and un-compacted value of the private-attribute section, `a`, field.
 
-As discussed above, the presence of the `i` field at the top level of the Attribute section block makes this a targeted Attribute section. The AID given by the `i` field value is the target entity called the Issuee. The semantics of the Issuee maybe defined by the Credential Frameworks in the EGF.
+As discussed above, the presence of the `i` field at the top level of the Attribute section block makes this a targeted Attribute section. The AID given by the `i` field value is the target entity called the Issuee. The semantics of the Issuee SHOULD be defined by the Credential Frameworks in the EGF.
 
 Given the presence of a top-level UUID, `u`, field of the Attribute block whose value has sufficient cryptographic entropy, then the top-level SAID, `d`, field of the Attribute block provides a secure cryptographic digest of the contents of the Attribute block [[48]]. An adversary when given both the Schema of the Attribute block and its SAID, `d`, field, is not able to discover the remaining contents of the attribute block in a computationally feasible manner such as a rainbow table attack [[30]] ] [[31]].  Therefore, the attribute block's UUID, `u`, field in a compact ACDC enables its Attribute block's SAID, `d`, field to securely blind the contents of the Attribute block notwithstanding knowledge of the Attribute block's Schema and SAID, `d` field.  Moreover, a cryptographic commitment to that Attribute block's, SAID, `d`, field does not provide a fixed point of correlation to the Attribute field values themselves unless and until there has been a disclosure of those field values.
 
-To elaborate, when an ACDC includes a sufficiently high entropy UUID, `u`, field at the top level of its Attributes block then the ACDC may be considered a private-attributes ACDC when expressed in compact form, that is, the Attribute block is represented by its SAID, `d`, field and the value of its top-level Attribute section, `a`, field is the value of the nested SAID, `d`, field from the uncompacted version of the Attribute block. A verifiable commitment may be made to the compact form of the ACDC without leaking details of the Attributes. Later disclosure of the uncompacted Attribute block may be verified against its SAID, `d`, field that was provided in the compact form as the value of the top-level Attribute section, `a`, field.
+To elaborate, when an ACDC includes a sufficiently high entropy UUID, `u`, field at the top level of its Attributes block then the ACDC MAY be considered a private-attributes ACDC when expressed in compact form, that is, the Attribute block is represented by its SAID, `d`, field and the value of its top-level Attribute section, `a`, field is the value of the nested SAID, `d`, field from the uncompacted version of the Attribute block. A verifiable commitment MAY be made to the compact form of the ACDC without leaking details of the Attributes. Later disclosure of the uncompacted Attribute block SHOULD be verified against its SAID, `d`, field that was provided in the compact form as the value of the top-level Attribute section, `a`, field.
 
 Because the Issuee AID is nested in the attribute block as that block's top-level, Issuee, `i`, field, a presentation exchange (disclosure) could be initiated on behalf of a different AID that has not yet been correlated to the Issuee AID and then only correlated to the Issuee AID after the Disclosee has agreed to the Chain-Link Confidentiality provisions in the rules section of the private-attributes ACDC [[44].
 
@@ -985,9 +994,9 @@ As described above in the Schema section of this specification, the `oneOf` subs
 
 The SAID, `d`, field at the top level of the uncompacted Attribute block is the same SAID used as the compacted value of the Attribute section, `a`, field.
 
-As discussed above, the presence of the `i` field at the top level of the Attribute section block makes this a targeted Attribute section. The AID given by the `i` field value is the Target or Issuee. The semantics of the issuance may be defined by the Credential Frameworks of the EGF.
+As discussed above, the presence of the `i` field at the top level of the Attribute section block makes this a targeted Attribute section. The AID given by the `i` field value is the Target or Issuee. The semantics of the issuance SHOULD be defined by the Credential Frameworks of the EGF.
 
-Given the absence of a `u` field at the top level of the Attributes block, however, knowledge of both SAID, `d`, field at the top level of an Attributes block and the schema of the Attributes block may enable the discovery of the remaining contents of the attributes block via a rainbow table attack [[30]] [[31]]. Therefore, the SAID, `d`, field of the Attributes block, although a cryptographic digest, does not securely blind the contents of the Attributes block given knowledge of the Schema. It only provides compactness, not privacy. Moreover, any cryptographic commitment to that SAID, `d`, field potentially provides a fixed correlation point to the attribute block field values despite the non-disclosure of those field values via a Compact Attribute section. Thus, an ACDC without a UUID, `u` field in its Attributes block must be considered a Public-Attribute ACDC even when expressed in compact form.
+Given the absence of a `u` field at the top level of the Attributes block, however, knowledge of both SAID, `d`, field at the top level of an Attributes block and the schema of the Attributes block may enable the discovery of the remaining contents of the attributes block via a rainbow table attack [[30]] [[31]]. Therefore, the SAID, `d`, field of the Attributes block, although a cryptographic digest, does not securely blind the contents of the Attributes block given knowledge of the Schema. It only provides compactness, not privacy. Moreover, any cryptographic commitment to that SAID, `d`, field potentially provides a fixed correlation point to the attribute block field values despite the non-disclosure of those field values via a Compact Attribute section. Thus, an ACDC without a UUID, `u` field in its Attributes block MUST be considered a Public-Attribute ACDC even when expressed in compact form.
 
 #### Nested partially disclosable Attribute section example
 
@@ -1145,13 +1154,13 @@ Notice that the compact form of the `grades` subblock has as the field value of
 
 ### Edge section  
 
-The Edge Section, `e` field appears as a top-level block within the ACDC and denotes the start of subsequent Edge-groups. The Edge Section has several reserved fields that may appear as top-level fields within its block.
+The Edge Section, `e` field MAY appear as a top-level block within the ACDC and denotes the start of subsequent Edge-groups. The Edge Section has several reserved fields that MAY appear as top-level fields within its block.
 
 #### Block types
 
-There are two types of field maps or blocks that may appear as values of fields within the Edge Section, `e` field either at the top level of the Edge block itself or nested. These are Edges or Edge-groups. Edges may only appear as locally unique labeled (using non-reserved labels) blocks nested within an Edge-group. There are two exceptions for Edges, compact and simple compact form. In these two forms the Edge field value is not a block but a string. These exceptions are defined below.
+There are two types of field maps or blocks that MAY appear as values of fields within the Edge Section, `e` field either at the top level of the Edge block itself or nested. These are Edges or Edge-groups. Edges MAY only appear as locally unique labeled (using non-reserved labels) blocks nested within an Edge-group. There are two exceptions for Edges, compact and simple compact form. In these two forms the Edge field value is not a block but a string. These exceptions are defined below.
 
-Nested Edge-groups may only appear as locally unique labeled blocks nested within another Edge-group. The block type, Edge or Edge-group, is indicated by its corresponding labeled subschema, with the exception of the top-level Edge-group, which is the Edge Section and is indicated by the Edge Section subschema. An Edge is indicated by the required presence of a node, `n` field in the non-compact variant of its subschema. An Edge-group shall not have a node, `n` field.
+Nested Edge-groups, when present, with one exception, MUST appear as locally unique labeled blocks nested within another Edge-group. The block type, Edge or Edge-group, is indicated by its corresponding labeled subschema. The exception is the top-level Edge-group, which is the Edge Section and is indicated by the Edge Section subschema. When present, it MUST appear at the top-level of the ACDC. The presence of an Edge Section is OPTIONAL, An Edge is indicated by the REQUIRED presence of a node, `n` field in the non-compact variant of its subschema. An Edge MUST contain a node, `n` field. An Edge-group MUST NOT have a node, `n` field.
 
 #### ACDCs as secure graph fragments of a globally distributed property graph (PG)
 
@@ -1159,11 +1168,11 @@ A set of ACDCs as nodes connected by edges forms a labeled property graph (LPG)
 
 To clarify, the Edge Section of an ACDC forms a sub-graph where each Edge block is a leaf of a branch in that sub-graph that terminates at the value of its node, `n`, field. Its node, `n` field, points to some other ACDC that is itself a sub-graph. The head of each sub-graph is the top-level Edge-group, i.e. the Edge Section. Thus, an Edge block is a leaf with respect to the sub-graph formed by any nested Edge-group blocks in which the Edge appears.  
 
-Abstractly, an ACDC with one or more edges may be viewed as a fragment of a larger distributed property graph where each ACDC Edge Section is a sub-graph. Each node in this larger graph is universally uniquely identified by the SAID of its ACDC. Recall that a SAID is a cryptographic digest. The local labels on each Edge block or Edge-group block are not universally uniquely resolvable, so they are inappropriate as a verifiable hook for resolving the Edges in a globally distributed property graph. This requires resolving both nodes and Edges. To enable both the node and its connecting edge to be globally uniquely resolvable, each Edge's block must also have a SAID, `d`, field. Recall that a SAID is a cryptographic digest. Therefore, it will universally and uniquely identify an Edge with a given set of properties [[48]], including the node it points to. 
+Abstractly, an ACDC with one or more edges may be viewed as a fragment of a larger distributed property graph where each ACDC Edge Section is a sub-graph. Each node in this larger graph is universally uniquely identified by the SAID of its ACDC. Recall that a SAID is a cryptographic digest. The local labels on each Edge block or Edge-group block are not universally uniquely resolvable, so they are inappropriate as a verifiable hook for resolving the Edges in a globally distributed property graph. This requires resolving both nodes and Edges. To enable both the node and its connecting edge to be globally uniquely resolvable, each Edge's block MUST also have a SAID, `d`, field. Recall that a SAID is a cryptographic digest. Therefore, it will universally and uniquely identify an Edge with a given set of properties [[48]], including the node it points to. 
 
 Thus, a given ACDC with its Edges may be universally uniquely resolvable as a graph fragment of a larger graph.  Moreover, because each ACDC with edges, i.e., a graph fragment, may be independently sourced and securely attributed, a distributed property graph can be securely assembled and verified fragment by fragment. To summarize, these features enable ACDCs to be used as securely attributed fragments of a globally distributed property graph (PG). This further enables such a property graph so assembled to serve as a global verifiable knowledge graph that crosses trust domains [[56]] [[57]] [[58]]. 
 
-The universal uniqueness of the ACDC SAIDs (nodes) and their Edge SAIDs enable the simplified discovery of ACDCs via service endpoints. The discovery of a service endpoint URL that provides database access to a copy of the ACDC may be bootstrapped via an OOBI (Out-Of-Band-Introduction) that links the service endpoint URL to the SAID of the ACDC or by the SAID of the Edge that points to the SAID of that ACDC [[4]]. Alternatively, the Issuer may provide as an attachment at the time of issuance a copy of the referenced ACDC. In either case, after a successful exchange, the Issuee of any ACDC will have either a copy or a means of obtaining a copy of any referenced ACDCs as nodes in the edge sections of all referenced ACDCs. That Issuee will then have everything it needs to make a successful disclosure to some other Disclosee. This is the essence of Percolated Discovery [[4]].
+The universal uniqueness of the ACDC SAIDs (nodes) and their Edge SAIDs enable the simplified discovery of ACDCs via service endpoints. The discovery of a service endpoint URL that provides database access to a copy of the ACDC MAY be bootstrapped via an OOBI (Out-Of-Band-Introduction) that links the service endpoint URL to the SAID of the ACDC or by the SAID of the Edge that points to the SAID of that ACDC [[4]]. Alternatively, the Issuer MAY provide as an attachment at the time of issuance a copy of the referenced ACDC. In either case, after a successful exchange, the Issuee of any ACDC will have either a copy or a means of obtaining a copy of any referenced ACDCs as nodes in the edge sections of all referenced ACDCs. That Issuee will then have everything it needs to make a successful disclosure to some other Disclosee. This is the essence of Percolated Discovery [[4]].
 
 #### Edge-group
 
@@ -1178,19 +1187,19 @@ The reserved field labels for an Edge-group are detailed in the table below.
 
 When present, the order of appearance of these fields is as follows: `[d, u, o, w]'.
 
-An Edge-group shall not have a node, `n`, field. 
+An Edge-group MUST NOT have a node, `n`, field. 
 
 ##### SAID, `d` field
 
-The SAID, `d` field is optional but when it appears it shall appear as the first field in the Edge-group block. The value of this field shall be the SAID of its enclosing block.
+The SAID, `d` field is optional but when it appears it MUST appear as the first field in the Edge-group block. The value of this field MUST be the SAID of its enclosing block.
 
 ##### UUID, `u` field
 
-The UUID, `u` field is optional, but when it appears, it shall appear as the second field in the Edge-group block following the SAID, `d`, field. The value of this field shall be a cryptographic strength salty-nonce with approximately 128 bits of entropy. When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [@Hash]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [@RB][@DRB].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
+The UUID, `u` field is optional, but when it appears, it MUST appear as the second field in the Edge-group block following the SAID, `d`, field. The value of this field MUST be a cryptographic strength salty-nonce with approximately 128 bits of entropy. When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [@Hash]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [@RB][@DRB].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
 
 ##### Operator, `o` field
 
-The Operator, `o` field must appear immediately following the SAID, `d` field, and UUID, `u` field (when present) in the Edge-group block. The Operator field in an Edge-group block is an aggregating (m-ary) operator on all the nested labeled Edges or Edge-groups that appear in its block. This differs from the Operator, `o` field in an Edge block (see below).
+The Operator, `o` field MUST appear immediately following the SAID, `d` field, and UUID, `u` field (when present) in the Edge-group block. The Operator field in an Edge-group block is an aggregating (m-ary) operator on all the nested labeled Edges or Edge-groups that appear in its block. This differs from the Operator, `o` field in an Edge block (see below).
 
 The m-ary operators are defined in the table below:
 
@@ -1203,33 +1212,33 @@ The m-ary operators are defined in the table below:
 |`AVG`| Arithmetic average of a given Edge-group member property. Averaged property is defined by the schema or EGF. | No |
 |`WAVG`| Weighted arithmetic average of a given Edge-group member property. Weight is given by the `w` field. Averaged property is defined by the Schema or EGF. | No |
 
-When the Operator, `o`, field is missing in an Edge-group block, the default value for the Operator, `o`, field shall be the `AND` Operator.
+When the Operator, `o`, field is missing in an Edge-group block, the default value for the Operator, `o`, field MUST be the `AND` Operator.
 
 The actual logic for interpreting the validity of a set of chained or treed ACDCs is EGF-dependent.  But as a default, at least at the time of issuance, a set of chained (treed) ACDCs can be interpreted as a provenance chain (tree) with the default logic explained below. ACDCs in a provenance chain or branch that have expiration dates or are dynamically revocable add a timeliness property to the validation logic in the event that the chain was unbroken at issuance but becomes broken later. The timeliness logic is EGF-dependent. 
 
-When the top-level Edge-group, the Edge Section includes only one Edge, the logic for evaluating the validity of the enclosing ACDC (near node) with respect to the validity of the connected far node ACDC pointed to by that edge may be considered a link in a provenance chain.  When any node in a provenance chain is invalid, an Edge pointing to that node is also invalid. If a node has an invalid Edge, then the node is invalid.  To elaborate, a chain of nodes with Edges has a head and a tail. The Edges are directed from the head to the tail. All links from the node at the head at one end of a chain to the tail at the other end must be valid in order for the node (head) to be valid. If any links between the head and the tail are broken (invalid), then the head is itself invalid. The unary operators (defined below) for edges enable modulation of the validation logic of a given Edge/node in a chain of ACDCs.
+When the top-level Edge-group, the Edge Section includes only one Edge, the logic for evaluating the validity of the enclosing ACDC (near node) with respect to the validity of the connected far node ACDC pointed to by that edge MAY be considered a link in a provenance chain.  When any node in a provenance chain is invalid, an Edge pointing to that node MAY also be invalid. If a node has an invalid Edge, then the node MAY also be invalid.  To elaborate, a chain of nodes with Edges has a head and a tail. The Edges are directed from the head to the tail. Typically, in a given EGF (ecosystem governance framework), all links from the node at the head at one end of a chain to the tail at the other end MUST be valid in order for the node (head) to be valid. If any links between the head and the tail are broken (invalid), then the head is itself MUST be invalid. The unary operators (defined below) for edges enable modulation of the validation logic of a given Edge/node in a chain of ACDCs.
 
-When the top-level Edge-group, the Edge Section includes more than one Edge directly or indirectly (as nested Edge(s) in nested Edge-group), then the logic for evaluating the validity of the enclosing ACDC (near node) with respect to the validity of all the connected far node ACDCs pointed to by those Edges may be a provenance tree.  Instead of a single chain from the head to a single tail, there is a tree with the truck at the head and branches as chains of directed Edges that each point to a branch tail (leaf) node. To clarify, each branch is a chain from head to branch tail.  All branches from the head must be valid for the head node to be valid. The m-ary Operators (defined above), in combination with the unary Operators (defined below), allow modulation of the validation aggregation logic of groups of Edges/nodes at each branch in a tree of ACDCs.
+When the top-level Edge-group, the Edge Section includes more than one Edge directly or indirectly (as nested Edge(s) in nested Edge-group), then the logic for evaluating the validity of the enclosing ACDC (near node) with respect to the validity of all the connected far node ACDCs pointed to by those Edges MAY be a provenance tree.  Instead of a single chain from the head to a single tail, there is a tree with the truck at the head and branches as chains of directed Edges that each point to a branch tail (leaf) node. To clarify, each branch is a chain from head to branch tail.  Typically, in a given EGF (ecosystem governance framework), all branches from the head MUST be valid for the head node to be valid. The m-ary Operators (defined above), in combination with the unary Operators (defined below), allow modulation of the validation aggregation logic of groups of Edges/nodes at each branch in a tree of ACDCs.
 
 ##### Weight, `w` field
 
-The Weight, `w` field must appear immediately following all of the SAID, `d` field, UUID, `u` field (when present), and Operator, `o` field (when present) in the Edge-group block. The Weight field enables weighted averages with Operators that perform some type of weighted average, such as the `WAVG` Operator. The top-level Edge-group shall not have a weight, `w` field, because it is not a member of another Edge-group.
+The Weight, `w` field, is OPTIONAL but when present, it MUST appear immediately following all of the SAID, `d` field, UUID, `u` field (when present), and Operator, `o` field (when present) in the Edge-group block. The Weight field enables weighted averages with Operators that perform some type of weighted average, such as the `WAVG` Operator. The top-level Edge-group MUST NOT have a weight, `w` field, because it is not a member of another Edge-group.
 
-A Edge-group with a weight provides an aggregate of weighted directed Edges. Weighted directed Edges may represent degrees of confidence or likelihood. PGs with weighted, directed Edges are commonly used for machine learning or reasoning under uncertainty. The Weight, `w` field provides a reserved label for the primary weight on an Edge group to be applied by the Operator of its enclosing Edge-group. To elaborate, many aggregating Operators used for automated reasoning, such as the weighted average, `WAVG`, Operator, or ranking aggregation Operators, depend on each input's weight. To simplify the semantics for such Operators, the Weight, `w`, field is the reserved field label for weighting. Other fields with other labels (labeled Edge-group properties) could provide other types of weights, but having a default label, namely `w`, simplifies the default definitions of weighted Operators.
+A Edge-group with a weight MAY provide an aggregate of weighted directed Edges. Weighted directed Edges MAY represent degrees of confidence or likelihood. PGs with weighted, directed Edges are commonly used for machine learning or reasoning under uncertainty. The Weight, `w` field provides a reserved label that MAY be the primary weight on an Edge group to be applied by the Operator of its enclosing Edge-group. To elaborate, many aggregating Operators used for automated reasoning, such as the weighted average, `WAVG`, Operator, or ranking aggregation Operators, depend on each input's weight. To simplify the semantics for such Operators, the Weight, `w`, field MUST be the reserved field label for weighting. Other fields with other labels (labeled Edge-group properties) MAY provide other types of weights, but having a default label, namely `w`, simplifies the default definitions of weighted Operators.
 
 ##### Labeled nested edge and edge-group fields
 
-Edge-groups and Edges nested within a given Edge-group appear as labeled fields whose labels are not any of the reserved field labels for either Edge-groups or Edges, namely, `[d, u, n, s, o, w]'. Labeled nested Edge or Edge-group fields must appear after all of any fields with a reserved field label.
+Edge-groups and Edges nested within a given Edge-group MAY appear as labeled fields whose labels are not any of the reserved field labels for either Edge-groups or Edges, namely, `[d, u, n, s, o, w]'. Such labeled nested Edge or Edge-group fields MUST appear after all of any fields with a reserved field label.
 
-Each nested Edge or Edge-group block within an Edge-group including the top-level Edge Section Edge-group shall be labeled with a locally unique non-reserved field label that indicates the type of the nested block. To clarify, each nested block in every Edge-group gets its own field with its own local (to the ACDC) label. The field's value may be either an Edge sub-block or when in compact form, a string. The compact forms are defined below.
+Each nested Edge or Edge-group block within an Edge-group including the top-level Edge Section Edge-group MUST be labeled with a locally unique non-reserved field label that indicates the type of the nested block. To clarify, each nested block in every Edge-group MUST have its own field with its own local (to the ACDC) label. The field's value MAY be either an Edge sub-block or when in compact form, a string. The compact forms are defined below.
 
-Note that each nested block shall not include a type field. The type of each block is provided by that associated subschema in the Edge Section's subschema with a matching label. This is in accordance with the design principle of ACDCs that may be succinctly expressed as "type-is-schema." This approach varies somewhat from other types of property graphs, which often do not have a Schema [[56]] [[57]] [[58]]. Because ACDCs have a Schema, they leverage it to provide property graph edge types with a cleaner separation of concerns. Notwithstanding this separation, an Edge block may include a constraint on the type of the ACDC to which that Edge points by including the SAID of the schema of the pointed-to ACDC as a property of that edge (see below).  
+Note that each nested block MUST NOT include a type field. The type of each block is provided by that associated subschema in the Edge Section's subschema with a matching label. This is in accordance with the design principle of ACDCs succinctly expressed as "type-is-schema." This approach varies somewhat from other types of property graphs, which often do not have a Schema [[56]] [[57]] [[58]]. Because ACDCs MUST have a Schema, they SHOULD leverage it to provide property graph edge types with a cleaner separation of concerns. Notwithstanding this separation, an Edge block MAY include a constraint on the type of the ACDC to which that Edge points by including the SAID of the schema of the pointed-to ACDC as a property of that edge (see below).  
 
-A main distinguishing feature of a property graph (PG) is that both nodes and Edges may have a set of properties [[56]] [[57]] [[58]]. These might include modifiers that influence how the connected node is to be combined or place a constraint on the allowed type(s) of connected nodes. Each Edge's block provides the Edge's properties vis-a-vis a property graph. Additional properties may be inferred from the properties of an enclosing Edge-group's block. Each labeled Edge and Edge-group type is defined by the subschema designated by its label. 
+A main distinguishing feature of a property graph (PG) including ACDCs is that both nodes and Edges MAY have a set of properties [[56]] [[57]] [[58]]. These MAY include modifiers that influence how the connected node is to be combined or place a constraint on the allowed type(s) of connected nodes. Each Edge's block provides the Edge's properties vis-a-vis a property graph. Additional properties MAY be inferred from the properties of an enclosing Edge-group's block. Each labeled Edge and Edge-group type MUST be defined by the subschema designated by its label. 
 
 #### Edge
 
-An Edge is typically represented as a block (field map). There are two exceptions, however, compact Edge form and simple compact Edge form. These are defined below. The Edge subschema is used to differentiate these two compact forms from the block form.
+An Edge MUST be represented as a block (field map) with two exceptions. These are: compact Edge form and simple compact Edge form. These are defined below. The Edge subschema is used to differentiate these two compact forms from the block form.
 
 The reserved field labels within an Edge block are defined in the table below.
 
@@ -1242,80 +1251,80 @@ The reserved field labels within an Edge block are defined in the table below.
 |`o`| Operator| Optional as either a unary operator on the Edge itself or an m-ary operator on the Edge-group in Edge section. Enables expression of the Edge logic on Edge subgraph.|
 |`w`| Weight| Optional edge weight property that enables default property for directed weighted edges and operators that use weights.|
 
-An Edge block shall have a node, `n`, field. This differentiates an Edge block from an Edge-group block.  The SAID, `d`, UUID, `u`, schema, `s`, operator, `o`, and weight, `w`  fields are optional. To clarify, each Edge block shall have a node, `n`, field and  may have any combination of SAID, `d`, UUID, `u`, schema, `s`, operator, `o`, or weight, `w` fields. When present the order of appearance of these fields is as follows: `[d, u, n, s, o, w]'.
+An Edge block MUST have a node, `n`, field. This differentiates an Edge block from an Edge-group block.  The SAID, `d`, UUID, `u`, schema, `s`, operator, `o`, and weight, `w`  fields are OPTIONAL. To clarify, each Edge block MUST have a node, `n`, field and MAY have any combination of SAID, `d`, UUID, `u`, schema, `s`, operator, `o`, or weight, `w` fields. When present the order of appearance of these fields MUST be as follows: `[d, u, n, s, o, w]'.
 
 
 ##### SAID, `d` field
 
-The SAID, `d` field is optional but, when present, shall appear as the first field in the Edge block. The value of this field shall be the SAID of its enclosing block.
+The SAID, `d` field is optional but, when present, MUST appear as the first field in the Edge block. The value of this field MUST be the SAID of its enclosing block.
 
 ###### Compact edge
 
-Given that an individual edge's property block includes a SAID, `d`, field, a compact representation of the edge's property block is provided by replacing it with its SAID. This is called a compact edge. The schema for that edge's label shall indicate that the edge value is the edge block SAID by using a `oneOf` composition of the compact form and the expanded form. This may be useful for compacting complex edges with many properties and then expanding them later. When the edge block also includes a UUID, `u` field then compating also hides the edge properties for later disclosure. A compact edge without a UUID, `u` field is a public compact edge.  A compact edge with a UUID, `u` field is a private compact edge. 
+Given that an individual edge's property block includes a SAID, `d`, field, a compact representation of the edge's property block is provided by replacing it with its SAID. This is called a compact edge. The schema for that edge's label MUST indicate that the edge value is the edge block SAID by using a `oneOf` composition of the compact form and the expanded form. This is useful for compacting complex edges with many properties and then expanding them later. When the edge block also includes a UUID, `u` field then compating also hides the edge properties for later disclosure. A compact edge without a UUID, `u` field is defined to be a public compact edge.  A compact edge with a UUID, `u` field is defined to be a private compact edge. 
 
 ##### UUID, `u` field
 
-The UUID, `u` field is optional, but when it appears, it shall appear as the second field in the Edge block following the SAID, `d`, field. The value of this field shall be a cryptographic strength salty-nonce with approximately 128 bits of entropy. When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
+The UUID, `u` field is optional, but when it appears, it MUST appear as the second field in the Edge block following the SAID, `d`, field. The value of this field MUST be a cryptographic strength salty-nonce with approximately 128 bits of entropy (nominally). When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
 
 The absence of the UUID, `u` field in an Edge block makes that edge a Public Edge. 
-The presence of the UUID, `u` field in an Edge block makes that Edge a Private Edge.  A Private Edge in compact form, i.e., a Compact Private Edge, enables a presenter of that ACDC to make a verifiable commitment to the ACDC attached to the Edge without disclosing any details of that ACDC, including the ACDC's SAID. Private ACDCs (nodes) and Private Edges may be combined to better protect the privacy of the information in a distributed property graph.
+The presence of the UUID, `u` field in an Edge block makes that Edge a Private Edge.  A Private Edge in compact form, i.e., a Compact Private Edge, enables a presenter of that ACDC to make a verifiable commitment to the ACDC attached to the Edge without disclosing any details of that ACDC, including the ACDC's SAID. Private ACDCs (nodes) and Private Edges MAY be combined to better protect the privacy of the information in a distributed property graph.
 
 
 ##### Node, `n` field
 
-When an Edge block does not include a SAID, `d` field, then the node, `n` field must appear as the first field in the block.
+When an Edge block does not include a SAID, `d` field, then the node, `n` field MUST appear as the first field in the block.
 
 The value of the required node, `n` field, is the SAID of the ACDC to which the Edge connects, i.e., the node, `n` field indicates, designates, references, links, or "points to" another ACDC called the far node. To clarify, the Edge is directed from the near node, i.e., the ACDC in which the Edge block resides, to the far node, which is the ACDC indicated by the value of node, `n` field of that block. The edges and nodes form a directed acyclic graph (DAG). 
 
-In order for a given Edge to be valid, at the very least, a Validator shall confirm that the SAID of the provided far node ACDC matches the node, `n` field value given in the near node ACDC Edge block and shall confirm that the provided far node ACDC satisfies its own schema. When the Edge block has a schema, `s` field is present (see below), then the far node shall also validate against the Schema indicated by the near node Edge's Schema, `s` field value.
+In order for a given Edge to be valid, at the very least, a Validator MUST confirm that the SAID of the provided far node ACDC matches the node, `n` field value given in the near node ACDC Edge block and MUST confirm that the provided far node ACDC satisfies its own schema. When the Edge block has a schema, `s` field is present (see below), then the far node MUST also validate against the Schema indicated by the near node Edge's Schema, `s` field value.
 
 
 ###### Simple compact edge
 
-When an Edge sub-block has only one field, that is, its node, `n` field, i.e., it has no other properties, then the Edge block may use an alternate simplified, compact form where the labeled Edge field value is the value of its node, `n,` field. The Edge is, therefore, public.  This enables the very compact expression of simple public Edges. The Schema for that Edge's label shall indicate that the Edge value is a far node SAID string and use a `oneOF` composition whose expanded block has only a Node, `n` field with the far node SAID as its value. 
+When an Edge sub-block has only one field, that is, its node, `n` field, i.e., it has no other properties, then the Edge block MAY use an alternate simplified, compact form where the labeled Edge field value is the value of its node, `n,` field. The Edge is, therefore, public.  This enables the very compact expression of simple public Edges. The Schema for that Edge's label MUST indicate that the Edge value is a far node SAID string and use a `oneOF` composition whose expanded block has only a Node, `n` field with the far node SAID as its value. 
 
 ##### Schema, `s` field
 
-When present, the Schema `s` field must appear immediately following the node `n` field in the Edge sub-block. The schema, `s` field provides an additional constraint on the far node ACDC. The far node ACDC shall also validate against an Edge block schema, `s` field when present.  To clarify, the Validator, after validating that the provided far node ACDC indicated by the node, `n` field satisfies its (the far ACDC's) own Schema, shall also confirm that far node ACDC passes Schema validation with respect to the Edge's `s` field value. This validation is simplified whenever the SAID of the far node ACDC Schema matches the SAID of the Edge's Schema, `s` field because only one Schema validation has to be performed. However, when the Schema SAIDs differ, two Schema validation runs shall be performed. The Edge Schema, `s` field enables a given Issuer of an ACDC to force forward compatibility constraints (i.e. minor schema version changes) on old ACDCs to which a new issuance is chained without having to add each old minor version to a list of `oneOf` compositions in the Edge's Schema, `s` field value. Major version changes are, by definition backwards breaking, so either the old version ACDC's must be revoked and reissued or the new Edge's schema value must include a `oneOf` composition that includes the old major versions. See the discussion under the Schema section for Schema versioning.
+When present, the Schema `s` field MUST appear immediately following the node `n` field in the Edge sub-block. The schema, `s` field provides an additional constraint on the far node ACDC. The far node ACDC MUST also validate against an Edge block schema, `s` field when present.  To clarify, the Validator, after validating that the provided far node ACDC indicated by the node, `n` field satisfies its (the far ACDC's) own Schema, MUST also confirm that far node ACDC passes Schema validation with respect to the Edge's `s` field value. This validation is simplified whenever the SAID of the far node ACDC Schema matches the SAID of the Edge's Schema, `s` field because only one Schema validation has to be performed. However, when the Schema SAIDs differ, two Schema validation runs MUST be performed. The Edge Schema, `s` field enables a given Issuer of an ACDC to force forward compatibility constraints (i.e. minor schema version changes) on old ACDCs to which a new issuance is chained without having to add each old minor version to a list of `oneOf` compositions in the Edge's Schema, `s` field value. Major version changes are, by definition backwards breaking, so either the old version ACDC's MUST be revoked and reissued or the new Edge's schema value MUST include a `oneOf` composition that includes the old major versions. See the discussion under the Schema section for Schema versioning.
 
 ##### Operator, `o` field
 
-The Operator, `o` field must appear immediately following the SAID, `d` field, UUID, `u` field, node, `n` field, or schema, `s` field (when present) in the Edge block. The Operator, `o`, field value in an Edge block is a unary Operator on the Edge itself. When more than one unary Operator is applied to a given Edge, then the value of the Operator, `o`, field is a list of those unary Operators. When multiple unary Operators appear in the list, and there is a conflict between Operators, the latest Operator among the conflicting Operators in the list takes precedence. This differs from the Operator, `o` field in an Edge-group block (see above).
+The Operator, `o` field MUST appear immediately following the SAID, `d` field, UUID, `u` field, node, `n` field, or schema, `s` field (when present) in the Edge block. The Operator, `o`, field value in an Edge block is a unary Operator on the Edge itself. When more than one unary Operator is applied to a given Edge, then the value of the Operator, `o`, field is a list of those unary Operators. When multiple unary Operators appear in the list, and there is a conflict between Operators, the latest Operator among the conflicting Operators in the list takes precedence. This differs from the Operator, `o` field in an Edge-group block (see above).
 
 The unary operators are defined in the table below:
 
 | Unary Operator | Description | Default|
 |:-:|:--|:--|:--|
-|`I2I`| Issuer-To-Issuee, The Issuer AID of this ACDC shall be the Issuee AID of the node this Edge points to.  | Yes |
-|`NI2I`| Not-Issuer-To-Issuee, The Issuer AID of this ACDC may or may not be the Issuee AID of the node that this Edge points to. |  No |
-|`DI2I`| Delegated-Issuer-To-Issuee, The Issuer AID of this ACDC must be either the Issuee AID or a delegated AID of the Issuee AID of the node this Edge points to. | No |
+|`I2I`| Issuer-To-Issuee, The Issuer AID of this ACDC MUST be the Issuee AID of the node this Edge points to.  | Yes |
+|`NI2I`| Not-Issuer-To-Issuee, The Issuer AID of this ACDC MAY or MAY not be the Issuee AID of the node that this Edge points to. |  No |
+|`DI2I`| Delegated-Issuer-To-Issuee, The Issuer AID of this ACDC MUST be either the Issuee AID or a delegated AID of the Issuee AID of the node this Edge points to. | No |
 |`NOT`| Logical NOT. The validity of the node this Edge points to is inverted. If valid, then not valid. If invalid, then valid.  | No |
 
 When the Operator, `o`, field is missing or empty or is present but does not include any of the `I2I`, `NI2I` or `DI2I` Operators then:
 
-- If the node pointed to by the Edge is a targeted ACDC, i.e., has an Issuee, then the `I2I` Operator shall be appended to the Operator, `o`, field's effective list value.
+- If the node pointed to by the Edge is a targeted ACDC, i.e., has an Issuee, then the `I2I` Operator MUST be appended to the Operator, `o`, field's effective list value.
 
-- If the node pointed to by the Edge block is an Untargeted ACDC i.e., does not have an Issuee, then the `NI2I` Operator shall be appended to the Operator, `o`, field's effective list value.
+- If the node pointed to by the Edge block is an Untargeted ACDC i.e., does not have an Issuee, then the `NI2I` Operator MUST be appended to the Operator, `o`, field's effective list value.
 
 Many ACDC chains use Targeted ACDCs (i.e., have Issuees). A chain of Issuer-To-Issuee-To-Issuer Targeted ACDCs in which each Issuee becomes the Issuer of the next ACDC in the chain can be used to provide a chain-of-authority. A common use case of a chain-of-authority is a delegation chain for authorization.
 
-The `I2I` unary operator, when present, means that the Issuer AID of the current ACDC in which the Edge resides must be the Issuee AID of the node to which the Edge points. Therefore, to be valid, the ACDC node pointed to by this Edge shall be a Targeted ACDC. This is the default value when the Operator 'o' field value is missing or empty.
+The `I2I` unary operator, when present, means that the Issuer AID of the current ACDC in which the Edge resides MUST be the Issuee AID of the node to which the Edge points. Therefore, to be valid, the ACDC node pointed to by this Edge MUST be a Targeted ACDC. This is the default value when the Operator 'o' field value is missing or empty.
 
-The `NI2I` unary Operator, when present, removes or nullifies any requirement expressed by the `I2I` Operator described above. In other words, any requirement that the Issuer AID of the current ACDC in which the Edge resides must be the Issuee AID, if any, of the node the Edge points to is relaxed (not applicable). To clarify, when operative (present), the `NI2I` Operator means that both an Untargeted ACDC or Targeted ACDC, as the node pointed to by the Edge, may be valid even when Untargeted or if Targeted even when the Issuer of the ACDC in which the Edge appears is not the Issuee AID, of that node to which the Edge points.
+The `NI2I` unary Operator, when present, removes or nullifies any requirement expressed by the `I2I` Operator described above. In other words, any REQUIREMENT that the Issuer AID of the current ACDC in which the Edge resides MUST be the Issuee AID, if any, of the node the Edge points to is relaxed (not applicable). To clarify, when operative (present), the `NI2I` Operator means that both an Untargeted ACDC or Targeted ACDC, as the node pointed to by the Edge, MAY be valid even when Untargeted or if Targeted even when the Issuer of the ACDC in which the Edge appears is not the Issuee AID, of that node to which the Edge points.
 
-The `DI2I` unary Operator, when present, expands the class of allowed Issuer AIDs of the node the Edge resides in to include not only the Issuee AID but also any delegated AIDs of the Issuee of the node to which the Edge points.  Therefore, to be valid, the ACDC node pointed to by this Edge shall be a Targeted ACDC.
+The `DI2I` unary Operator, when present, expands the class of allowed Issuer AIDs of the node the Edge resides in to include not only the Issuee AID but also any delegated AIDs of the Issuee of the node to which the Edge points.  Therefore, to be valid, the ACDC node pointed to by this Edge MUST be a Targeted ACDC.
 
 The `NOT` unary Operator, when present, inverts the validation truthiness of the node pointed to by this Edge. If this Edge's far node ACDC is invalid, then the presence of the `NOT` operator makes this Edge valid. Conversely, if this Edge's far node ACDC is valid, then the presence of the `NOT` Operator makes this Edge invalid.     
 
 ###### Weight, `w` field.
 
-The Weight, `w` field must appear immediately following the SAID, `d` field, UUID, `u` field, Node, `n` field, Schema, `s` field, or Operator, `o` field (when present) in the Edge block. The Weight field enables weighted direct Edges. The weighted directed Edges within an enclosing Edge-group may be aggregated when that Edge-group's Operator performs some type of weighted average.
+The Weight, `w` field MUST appear immediately following the SAID, `d` field, UUID, `u` field, Node, `n` field, Schema, `s` field, or Operator, `o` field (when present) in the Edge block. The Weight field enables weighted direct Edges. The weighted directed Edges within an enclosing Edge-group MAY be aggregated when that Edge-group's Operator performs some type of weighted average.
 
 Weighted directed Edges may represent degrees of confidence or likelihood. PGs with weighted, directed Edges are commonly used for machine learning or reasoning under uncertainty. The Weight, `w` field provides a reserved label for the primary Weight on an Edge. To elaborate, many aggregating operators used for automated reasoning, such as the weighted average, `WAVG`, Operator, or ranking aggregation Operators, depend on each input's Weight. To simplify the semantics for such Operators, the Weight, `w` field is the reserved field label for weighting. Other fields with other labels (labeled Edge properties) could provide other types of weights, but having a default label, namely `w` simplifies the default definitions of weighted Operators.
 
 ##### Labeled property fields
 
-Edge property fields appear as labeled fields whose labels are not any of the reserved field labels for either Edge-groups or Edges, namely, `[d, u, n, s, o, w].' Labeled property fields must appear after all of any fields with a reserved field label.
+Edge property fields appear as labeled fields whose labels are not any of the reserved field labels for either Edge-groups or Edges, namely, `[d, u, n, s, o, w].' Labeled property fields MUST appear after all of any fields with a reserved field label.
 
 
 
@@ -2032,13 +2041,13 @@ As the examples above have shown, the Edge Section syntax enables the composable
 
 The Rule Section, `r` field appears as a top-level block within the ACDC and denotes the start of subsequent Rule-groups. The purpose of the Rules section is to provide a set of rules or conditions as a Ricardian Contract [[43]]. The important features of a Ricardian contract are that it is both human and machine-readable and referenceable by a cryptographic digest. A JSON-encoded document or block, such as the Rules section block, is a practical example of both a human and machine-readable document.  The Rules section's top-level SAID, `d` field provides the digest.  This provision supports the bow-tie model of RC. 
 
-The Rules Section includes labeled nested blocks called Rules that provide the legal language (terms , conditions, definitions etc). The labeled clauses can be structured hierarchically, where each Rule, in turn, can include nested labeled Rules. The labels on the Rules may follow a structured naming or numbering convention. These provisions enable the Rules section to satisfy the features of an RC. 
+The Rules Section includes labeled nested blocks called Rules that provide the legal language (terms , conditions, definitions etc). The labeled clauses can be structured hierarchically, where each Rule, in turn, can include nested labeled Rules. The labels on the Rules MAY follow a structured naming or numbering convention. These provisions enable the Rules section to satisfy the features of an RC. 
 
 #### Block types
 
-There are two types of field maps or blocks that may appear as values of fields within the Rule Section, `r` field either at the top level of the Rule block itself or nested. These are Rules or Rule-groups. Rules may only appear as locally unique labeled (using non-reserved labels)  blocks nested within an Rule-Group. There are two exceptional forms for Rules, compact and simple compact form. In these two forms, the labeled Rule field value is not a block but a string. These exceptions are defined below.
+There are two types of field maps or blocks that MAY appear as values of fields within the Rule Section, `r` field either at the top level of the Rule block itself or nested. These are Rules or Rule-groups. Rules MAY only appear as locally unique labeled (using non-reserved labels)  blocks nested within an Rule-Group. There are two exceptional forms for Rules, compact and simple compact form. In these two forms, the labeled Rule field value is not a block but a string. These exceptions are defined below.
 
-Nested Rule-groups may only appear as locally unique labeled blocks nested within another Rule-group. The block type, Rule or Rule-group, is indicated by its corresponding labeled subschema, with the exception of the top-level Rule-group, which is the Rules Section and is indicated by the Rules Section subschema. A Rule-group is indicated by the presence of one or more non-reserved labeled fields whose value represents a nested Rule or Rule-Groups.  
+Nested Rule-groups MAY only appear as locally unique labeled blocks nested within another Rule-group. The block type, Rule or Rule-group, is indicated by its corresponding labeled subschema, with the exception of the top-level Rule-group, which is the Rules Section and is indicated by the Rules Section subschema. A Rule-group is indicated by the presence of one or more non-reserved labeled fields whose value represents a nested Rule or Rule-Groups.  
 
 #### Rule discovery 
 
@@ -2056,25 +2065,25 @@ The reserved field labels for Rule-groups are detailed in the table below.
 
 When present, the order of appearance of these fields is as follows: `[d, u, l]`.
 
-A Rule-group may have a Legal, `l`, field and may have a SAID, `d` field. When the Rule-group has a SAID, `d` field it may also have a UUID, `u` field. A Rule-group may have one or more other labeled fields whose values represent nested Rules or Rule-groups. In this sense, a Rule-group is an intermediate node in a sub-graph of Rule-groups and Rules.
+A Rule-group MAY have a Legal, `l`, field and MAY have a SAID, `d` field. When the Rule-group has a SAID, `d` field it MAY also have a UUID, `u` field. A Rule-group MAY have one or more other labeled fields whose values represent nested Rules or Rule-groups. In this sense, a Rule-group is an intermediate node in a sub-graph of Rule-groups and Rules.
 
 ##### SAID, `d` field
 
-The SAID, `d` field is optional but when it appears it shall appear as the first field in the Rule-group block. The value of this field shall be the SAID of its enclosing block. To elaborate, when the Rule-group is the top-level Rule Section its SAID is the same SAID used as the compacted value of the Rule Section, `r` field that appears at the top level of the ACDC. When not the top-level Rule-group, a given nested Rule-group's SAID, `d` field enables a verifiable globally unique reference to that nested Rule-group, not merely the whole contract as given by the Rule section's top-level SAID, `d`, field.
+The SAID, `d` field is optional but when it appears it MUST appear as the first field in the Rule-group block. The value of this field MUST be the SAID of its enclosing block. To elaborate, when the Rule-group is the top-level Rule Section its SAID is the same SAID used as the compacted value of the Rule Section, `r` field that appears at the top level of the ACDC. When not the top-level Rule-group, a given nested Rule-group's SAID, `d` field enables a verifiable globally unique reference to that nested Rule-group, not merely the whole contract as given by the Rule section's top-level SAID, `d`, field.
 
 ##### UUID, `u` field
 
-The UUID, `u` field is optional, but when it appears, it shall appear as the second field in the Rule-group block following the SAID, `d`, field. The value of this field shall be a cryptographic strength salty-nonce with approximately 128 bits of entropy. When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [@Hash]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [@RB][@DRB].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
+The UUID, `u` field is optional, but when it appears, it MUST appear as the second field in the Rule-group block following the SAID, `d`, field. The value of this field MUST be a cryptographic strength salty-nonce with approximately 128 bits of entropy (nominally). When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [@Hash]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [@RB][@DRB].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
 
 ##### Labeled nested rule and rule-group fields
 
-Rules and Rule-group nested within a Rule-group appear as labeled fields whose labels are not any of the reserved field labels for a Rule-group, namely, `[d, u, l]`. Labeled nested Rule or Rule-group fields must appear after all of any fields with a reserved field label. 
+Rules and Rule-group nested within a Rule-group appear as labeled fields whose labels are not any of the reserved field labels for a Rule-group, namely, `[d, u, l]`. Labeled nested Rule or Rule-group fields MUST appear after all of any fields with a reserved field label. 
 
-To elaborate, each nested Rule or Rule-group block shall be labeled with a locally unique non-reserved field label that indicates the type of the nested block. To clarify, each nested block gets its own field with its own local (to the ACDC Rule Section) label. The field's value may be either the Rule or Rule-group block or, in compact form, a string. The compact forms are defined below.
+To elaborate, each nested Rule or Rule-group block MUST be labeled with a locally unique non-reserved field label that indicates the type of the nested block. To clarify, each nested block gets its own field with its own local (to the ACDC Rule Section) label. The field's value MAY be either the Rule or Rule-group block or, in compact form, a string. The compact forms are defined below.
 
-Note that each nested block shall not include a type field. The type of each block is provided by that associated nested subschema with a matching label. This is in accordance with the design principle of ACDCs that may be succinctly expressed as "type-is-schema." This approach varies somewhat from other types of property graphs, which often do not have a Schema [[56]][[57]][[58]]. Because ACDCs have a Schema, they leverage it to provide property graph types with a cleaner separation of concerns.   
+Note that each nested block MUST NOT include a type field. The type of each block is provided by that associated nested subschema with a matching label. This is in accordance with the design principle of ACDCs succinctly expressed as "type-is-schema." This approach varies somewhat from other types of property graphs, which often do not have a Schema [[56]][[57]][[58]]. Because ACDCs have a Schema, they leverage it to provide property graph types with a cleaner separation of concerns.   
 
-A main distinguishing feature of a property graph (PG) is that both nodes and Edges may have a set of properties [[56]][[57]][[58]].  Each Rule-group's block provides its additional properties vis-a-vis a property graph as labeled fields. Additional properties may be inferred from the properties of an enclosing Rule-group block. Each labeled Rule type is defined by the subschema designated by its label. 
+A main distinguishing feature of a property graph (PG) including ACDCs is that both nodes and Edges MAY have a set of properties [[56]][[57]][[58]].  Each Rule-group's block MAY provide its additional properties vis-a-vis a property graph as labeled fields. Additional properties MAY be inferred from the properties of an enclosing Rule-group block. Each labeled Rule type MUST be defined by the subschema designated by its label. 
 
 
 #### Rule
@@ -2089,18 +2098,18 @@ The reserved field labels for a Rule block are detailed in the table below.
 
 When present, the order of appearance of these fields is as follows: `[d, u, l]`.
 
-A Rule shall have a Legal, `l`, field. And may have a SAID, `d` field. When the Rule has a SAID, `d` field, it may also have a UUID, `u` field. A Rule shall not have any other fields. In this sense, a Rule is a terminal node in a sub-graph of Rule-groups and Rules.
+A Rule MUST have a Legal, `l`, field. And MAY have a SAID, `d` field. When the Rule has a SAID, `d` field, it MAY also have a UUID, `u` field. A Rule MUST NOT have any other fields. In this sense, a Rule is a terminal node in a sub-graph of Rule-groups and Rules.
 
 ##### SAID, `d` field
-The SAID, `d` field is optional, but when it appears, it shall appear as the first field in the Clause block. The value of this field shall be the SAID of its enclosing block. A Rule's SAID enables a verifiable globally unique reference to that rule, not merely the whole contract as given by the Rule section's top-level SAID, `d`, field.
+The SAID, `d` field is optional, but when it appears, it MUST appear as the first field in the Clause block. The value of this field MUST be the SAID of its enclosing block. A Rule's SAID enables a verifiable globally unique reference to that rule, not merely the whole contract as given by the Rule section's top-level SAID, `d`, field.
 
 ##### Compact Rule
 
-Given that an individual Rule block includes a SAID, `d` field, a compact representation of the Rule's block is provided by replacing it with its SAID. This is called a compact Rule. The Schema for that clause's label shall indicate that the clause field value is the clause block SAID by using a `oneOf` composition of the compact form and the expanded form. This may be useful for compacting lengthy clauses and then expanding them later. When the clause block also includes a UUID, `u` field, then compacting also hides the clause's legal language for later disclosure. A compact clause without a UUID, `u` field is a public compact clause.  A compact clause with a UUID, `u` field is a private compact clause. 
+Given that an individual Rule block includes a SAID, `d` field, a compact representation of the Rule's block is provided by replacing it with its SAID. This is called a compact Rule. The Schema for that clause's label MUST indicate that the clause field value is the clause block SAID by using a `oneOf` composition of the compact form and the expanded form. This may be useful for compacting lengthy clauses and then expanding them later. When the clause block also includes a UUID, `u` field, then compacting also hides the clause's legal language for later disclosure. A compact clause without a UUID, `u` field is defined to be a public compact clause.  A compact clause with a UUID, `u` field is defined to be a private compact clause. 
 
 ##### UUID, `u` field
 
-The UUID, `u` field is optional, but when it appears, it shall appear as the second field in the Rule Section block following the SAID, `d` field. The value of this field shall be a cryptographic strength salty-nonce with approximately 128 bits of entropy. When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
+The UUID, `u` field is optional, but when it appears, it MUST appear as the second field in the Rule Section block following the SAID, `d` field. The value of this field MUST be a cryptographic strength salty-nonce with approximately 128 bits of entropy. When present, the UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's subschema and its SAID, cannot discover the remaining contents of the block in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's subschema and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's field values themselves unless and until there has been a disclosure of those field values.
 
 ##### Legal, `l` field
 
@@ -2109,13 +2118,13 @@ The legal language, `l`, field in each clause block provides the associated lega
 
 ##### Simple compact Rule
 
-When a Rule block has only one field, that is, its legal, `l` field, i.e., it has no other properties, then the rule block may use an alternate simplified, compact form where the labeled rule field value is the value of its legal, `l` field. The rule is, therefore, public.  This enables the very compact expression of simple public Rules. The Schema for that Rule's label shall indicate that the Rule's compact value is the value of its Legal, `l` field in expanded form and use a `oneOF` composition whose expanded block has only a Legal, `l` field.
+When a Rule block has only one field, that is, its legal, `l` field, i.e., it has no other properties, then the rule block MAY use an alternate simplified, compact form where the labeled rule field value is the value of its legal, `l` field. The rule is, therefore, public.  This enables the very compact expression of simple public Rules. The Schema for that Rule's label MUST indicate that the Rule's compact value is the value of its Legal, `l` field in expanded form and use a `oneOF` composition whose expanded block has only a Legal, `l` field.
 
 #### Rule section examples
 
 ##### Private rules
 
-Some Rules and Rule-groups, as opposed to the Rule Section as a whole, may benefit from confidential disclosure. Recall that individual Rule and Rule-group blocks may have their own SAID, `d`, field and UUID, `u,` field. To clarify, a Rule or Rule-group block with both a SAID, `d`, and UUID, `u` fields, where that UUID has sufficiently high entropy, protects the compact form of that block from discovery via a rainbow table attack merely from its SAID and subschema [[30]] [[31]]. Therefore, such a Rule or Rule-group may kept hidden until later disclosure. These are called private Rules or Rule-groups. The following example has an independently hidable Rule-group and Rules.
+Some Rules and Rule-groups, as opposed to the Rule Section as a whole, may benefit from confidential disclosure. Recall that individual Rule and Rule-group blocks MAY have their own SAID, `d`, field and UUID, `u,` field. To clarify, a Rule or Rule-group block with both a SAID, `d`, and UUID, `u` fields, where that UUID has sufficiently high entropy, protects the compact form of that block from discovery via a rainbow table attack merely from its SAID and subschema [[30]] [[31]]. Therefore, such a Rule or Rule-group may kept hidden until later disclosure. These are called private Rules or Rule-groups. The following example has an independently hidable Rule-group and Rules.
 
 Issued by Amy:
 
@@ -2379,7 +2388,7 @@ Notice that the value of the Rules Section's UUID, `d` field matches the value o
 
 #### Simple compact public Rules
 
-When there is no benefit to a private Rules section, then its UUID fields are not needed. Moreover, for the Rules themselves do not benefit from a dedicated SAID, `d` field. Given this change, the Rules section can be expressed in a compact form with simple compact Rules. Recall that in simple, compact form, each Rule block shall not have any fields besides the Legal, `l` field. This field value then becomes the value of the labeled Rule block.
+When there is no benefit to a private Rules section, then its UUID fields are not needed. Moreover, for the Rules themselves do not benefit from a dedicated SAID, `d` field. Given this change, the Rules section can be expressed in a compact form with simple compact Rules. Recall that in simple, compact form, each Rule block MUST NOT have any fields besides the Legal, `l` field. This field value then becomes the value of the labeled Rule block.
 
 Issued by Amy:
 
@@ -2635,7 +2644,7 @@ There are several graduated disclosure mechanisms as follows:
 
 As their names suggest, the Graduated Disclosure mechanisms disclose more or less of an ACDC. A short summary of each mechanism is provided immediately below. More detailed descriptions of each of the Graduated Disclosure mechanisms are either provided in the ensuing sections or in the Annex.
 
-- Compact Disclosure of a block (field map) of data relies on the inclusion in that block of a cryptographic digest of the content (SAID) of that content. Disclosure of the SAID makes a verifiable commitment to its data that may be more fully disclosed later. The Schema for the block includes a `oneOf` composition Operator that validates against both the compact and full versions of the block.
+- Compact Disclosure of a block (field map) of data relies on the inclusion in that block of a cryptographic digest of the content (SAID) of that content. Disclosure of the SAID makes a verifiable commitment to its data that MAY be more fully disclosed later. The Schema for the block MUST include a `oneOf` composition Operator that validates against both the compact and full versions of the block.
 
 - Metadata Disclosure happens with a Metadata ACDC is used to disclose any part of an ACDC. As defined above, a Metadata ACDC is indicated by the appearance of an empty, top-level UUID, `u`, field. Recall that the purpose of a metadata ACDC is to provide a mechanism for a Discloser to make cryptographic commitments to the metadata of a yet-to-be-disclosed private ACDC without providing any point of correlation to the actual top-level SAID, `d`, the field of that yet-to-be disclosed ACDC. 
 
@@ -2645,11 +2654,11 @@ As their names suggest, the Graduated Disclosure mechanisms disclose more or les
 
 - Full Disclosure is disclosure without hiding a given block's content behind SAIDs or salted SAIDs.
 
-- Selective Disclosure of a set of data blocks relies on each element embedding its digest (said) and salty nonce (UUID) as partially disclosable elements. The Schema for such a set is unordered such that the disclosure of any element does not leak information about any other element. This requires a combination of an `anyOf` composition Operator at the set level and `oneOf` composition Operators for each element. Membership in the set can be verified against a set of SAIDs, one from each element. The salty nonce effectively blinds the element's contents when only its SAID is disclosed. The `anyOf` composition Operator is not order-dependent. This means that the selectively disclosable set can be provided as an ordered list of elements, yet one or more of its elements may be disclosed in any order so that the original order does not leak information.
+- Selective Disclosure of a set of data blocks relies on each element embedding its digest (said) and salty nonce (UUID) as partially disclosable elements. The Schema for such a set is unordered such that the disclosure of any element does not leak information about any other element. This requires a combination of an `anyOf` composition Operator at the set level and `oneOf` composition Operators for each element. Membership in the set can be verified against a set of SAIDs, one from each element. The salty nonce effectively blinds the element's contents when only its SAID is disclosed. The `anyOf` composition Operator is not order-dependent. This means that the selectively disclosable set can be provided as an ordered list of elements, yet one or more of its elements MAY be disclosed in any order so that the original order does not leak information.
 
 - Bulk-issued Instance Disclosure relies on issuing multiple instances of a given ACDC, each a copy but with unique instance identifiers so that the disclosure of one instance is not correlatable to another via the instance identifiers.
 
-All the Graduated Disclosure mechanisms may be used in combination.
+All the Graduated Disclosure mechanisms MAY be used in combination.
 
 A salient difference between Partial Disclosure and Selective Disclosure of a given block is the degree to which information about other fields is exposed in order to make Full Disclosure of its detailed field values. A partially disclosable block, when fully disclosed, exposes, at the very least, the labels of other fields in its enclosing block (a field map). Whereas a selectively disclosable block, when fully disclosed, does not expose any information about other yet-to-be-exposed fields, including their labels in its enclosing block (a field map array). 
 
@@ -2662,17 +2671,16 @@ Graduated Disclosure enables a comprehensive protection mechanism called Contrac
 - Chain-Link Confidentiality Disclosure
 - Contingent Disclosure
 
-In a Contractually Protected Disclosure, the potential Discloser first makes an offer using the least (Partial) Disclosure of some information about other information to be disclosed (Full Disclosure) contingent on the potential Disclosee first agreeing to the contractual terms provided in the offer. The contractual terms could, for example, limit the disclosure to third parties of the yet to be disclosed information. But those contractual terms may also include provisions that protect against liability or other concerns, not merely disclosure to third parties. The process by which such least disclosures progress to full disclosure is described in the IPEX (Issuance and Exchange Protocol) section below.
+In a Contractually Protected Disclosure, the potential Discloser first makes an offer using the least (Partial) Disclosure of some information about other information to be disclosed (Full Disclosure) contingent on the potential Disclosee first agreeing to the contractual terms provided in the offer. The contractual terms could, for example, limit the disclosure to third parties of the yet to be disclosed information. But those contractual terms MAY also include provisions that protect against liability or other concerns, not merely disclosure to third parties. The process by which such least disclosures progress to full disclosure is described in the IPEX (Issuance and Exchange Protocol) section below.
 
-One special case of a Contractually protected disclosure is a Chain-Link Confidential disclosure [[44]. Chain-Link Confidentiality imposes conditions and limitations on the further disclosure and/or use of the disclosed data. These may be specific terms of use or other consensual constraints. These terms may be applied to subsequent disclosures by the Disclosee that follow the data (hence chain-link). Another way of viewing Chain-link confidential disclosure is that the disclosed data has "strings attached." The chaining, in this case, is different from the chaining of ACDCs via their edges, i.e., a DAG of ACDCs. Chain-link confidentiality, in contrast, chains together a sequence of Disclosees. Each Disclosee in the sequence, in turn, is the Discloser to the next Disclosee. The terms-of-use of the original disclosure as applied to the original Disclosee shall be applied by each subsequent Discloser to each subsequent Disclosee via each of the subsequent disclosures.  These terms of use are meant to contractually protect the data rights of the original Issuer or Issuee of the data being disclosed. These terms of use typically constrain disclosure to only approved parties, i.e., imbue the chain of disclosures with some degree of confidentiality.
+One special case of a Contractually protected disclosure is a Chain-Link Confidential disclosure [[44]. Chain-Link Confidentiality imposes conditions and limitations on the further disclosure and/or use of the disclosed data. These MAY be specific terms of use or other consensual constraints. These terms MAY be applied to subsequent disclosures by the Disclosee that follow the data (hence chain-link). Another way of viewing Chain-link confidential disclosure is that the disclosed data has "strings attached." The chaining, in this case, is different from the chaining of ACDCs via their edges, i.e., a DAG of ACDCs. Chain-link confidentiality, in contrast, chains together a sequence of Disclosees. Each Disclosee in the sequence, in turn, is the Discloser to the next Disclosee. The terms-of-use of the original disclosure as applied to the original Disclosee MUST be applied by each subsequent Discloser to each subsequent Disclosee via each of the subsequent disclosures.  These terms of use are meant to contractually protect the data rights of the original Issuer or Issuee of the data being disclosed. These terms of use typically constrain disclosure to only approved parties, i.e., imbue the chain of disclosures with some degree of confidentiality.
 
-Another special case of Contractually Protected Disclosure is Contingent Disclosure. In a Contingent Disclosure, some contingency is specified in the Rules section that places an obligation by some party to make a disclosure when the contingency is satisfied. This might be recourse given the breach of some other contract term. When that contingency is met, then the Contingent Disclosure must be made by the party whose responsibility it is to satisfy that disclosure obligation. The responsible party may be the Discloser, or it may be some other party, such as an escrow agent. The Contingent Disclosure clause may reference a cryptographic commitment to a private ACDC or private Attribute ACDC (Partial Disclosure) that satisfies via its Full Disclosure the Contingent Disclosure requirement. Contingent Disclosure may be used to limit the actual disclosure of personally identifying information (PII) to a just-in-time, need-to-know basis (i.e., upon the contingency) and not a priori. As long as the Discloser and Disclosee trust the escrow agent and the verifiability of the commitment, there is no need to disclose PII about the Discloser in order to enable a transaction, but merely an agreement to the terms of the contingency. This enables something called latent accountability. Recourse via Full Disclosure of PII is latent in the Contingent Disclosure but never realized (actualized) until the conditions of the contingency is satisfied. This minimizes inadvertent leakage while protecting both the Discloser and the Disclosee.
+Another special case of Contractually Protected Disclosure is Contingent Disclosure. In a Contingent Disclosure, some contingency is specified in the Rules section that places an obligation by some party to make a disclosure when the contingency is satisfied. This might be recourse given the breach of some other contract term. When that contingency is met, then the Contingent Disclosure MUST be made by the party whose responsibility it is to satisfy that disclosure obligation. The responsible party MAY be the Discloser, or it MAY be some other party, such as an escrow agent. The Contingent Disclosure clause MAY reference a cryptographic commitment to a private ACDC or private Attribute ACDC (Partial Disclosure) that satisfies via its Full Disclosure the Contingent Disclosure requirement. Contingent Disclosure MAY be used to limit the actual disclosure of personally identifying information (PII) to a just-in-time, need-to-know basis (i.e., upon the contingency) and not a priori. As long as the Discloser and Disclosee trust the escrow agent and the verifiability of the commitment, there is no need to disclose PII about the Discloser in order to enable a transaction, but merely an agreement to the terms of the contingency. This enables something called latent accountability. Recourse via Full Disclosure of PII is latent in the Contingent Disclosure but never realized (actualized) until the conditions of the contingency is satisfied. This minimizes inadvertent leakage while protecting both the Discloser and the Disclosee.
 
 
 ## Issuance and Presentation Exchange (IPEX)
 
-The Issuance and Presentation Exchange (IPEX) Protocol provides a uniform mechanism for the issuance and presentation of ACDCs [[ref: ACDC]] in a securely attributable manner. A single protocol is able to work for both types of exchanges by recognizing
-that all exchanges (both issuance and presentation) may be modeled as the disclosure of information by a Discloser to a Disclosee. 
+The Issuance and Presentation Exchange (IPEX) Protocol provides a uniform mechanism for the issuance and presentation of ACDCs [[ref: ACDC]] in a securely attributable manner. A single protocol is able to work for both types of exchanges by recognizing that all exchanges (both issuance and presentation) MAY be modeled as the disclosure of information by a Discloser to a Disclosee. This specification is not exhaustive, it is only normative in the sense that it specifies the message types and routes that SHOULD be used in either issuance or presentation exchanges. It provides sufficient detail to show a likely mechanism for implementing the various Graduated Disclosure mechanisms described above. A given implementation of issuance and or presentation exchange is typically application and ecosystem-dependent and would, therefore, require additional specifications for issuance and/or presentation exchange tuned to those application and ecosystem contexts. This specification provides a baseline for other specifications.
 
 The difference between exchange types is the information disclosed, not the mechanism for disclosure. Furthermore, the chaining mechanism of ACDCs and support for both Targeted and Untargeted ACDCs provide sufficient variability to accommodate the differences in applications or use cases without requiring a difference in the exchange protocol itself. This greatly simplifies the exchange protocol. This simplification has two primary advantages. The first is enhanced security. A well-delimited protocol can be designed and analyzed to minimize and mitigate attack mechanisms.
 
@@ -2682,6 +2690,8 @@ This IPEX [[ref: IPEX]] protocol leverages important features of ACDCs and ancil
 
 ### Exchange Protocol
 
+The baseline exchange protocol is composed of a standard set of routed KERI exchange, `exn` messages. The REQUIRED routes MUST appear as values of the route, `r` field in the enclosing exchange message. The notional semantics of each route indicate how the message SHOULD be used in an exchange. The routes and semantics are delimited in the following table:
+
 | Discloser | Disclosee | Initiate | Contents | Description |
 |:-:|:-:|:-:|:--|:--|
 | | `apply`| Y | Schema or its SAID, Attribute field label list, signature on `apply` or its SAID | Schema SAID is type of ACDC, optional label list for Selective Disclosure, CESR-Proof signature|
@@ -2695,51 +2705,51 @@ This IPEX [[ref: IPEX]] protocol leverages important features of ACDCs and ancil
 
 #### Commitments via SAID
 
-All the variants of an ACDC have various degrees of expansion of the compact variant. Therefore, an Issuer commitment via a signature (direct) or KEL anchored seal (indirect) to any variant of ACDC (metadata, compact, partial, nested partial, full, selective, etc.)  makes a cryptographic commitment to the top-level section fields shared by all variants of that ACDC because the value of a top-level section field is either the SAD or the SAID of the SAD of the associated section. Both a SAD and its SAID, when signed or sealed, each provide a verifiable commitment to the SAD. In the former, the signature or seal verification is directly against the SAD itself. In the latter, the SAID as digest must first be verified against its SAD, and then the signature or seal on the SAID may be verified. This indirect verifiability (one or multiple levels of commitment via cryptographic digests) assumes that the cryptographic strength of the SAID digest is equivalent to the cryptographic strength of the signature used to sign it. To clarify, because all variants share the same top-level structure as the compact variant, then a signature on any variant may be used to verify the Issuer's commitment to any other variant either directly or indirectly, in whole or in part on a top-level section by top-level section basis. This cross-variant Issuer commitment verifiability is an essential property that supports Graduated Disclosure by the Disclosee of any or all variants, whether Full, Compact, Metadata, Partial, Selective etc.
+All the variants of an ACDC have various degrees of expansion of the compact variant. Therefore, an Issuer commitment via a signature (direct) or KEL anchored seal (indirect) to any variant of ACDC (metadata, compact, partial, nested partial, full, selective, etc.)  makes a cryptographic commitment to the top-level section fields shared by all variants of that ACDC because the value of a top-level section field is either the SAD or the SAID of the SAD of the associated section. Both a SAD and its SAID, when signed or sealed, each provide a verifiable commitment to the SAD. In the former, the signature or seal verification is directly against the SAD itself. In the latter, the SAID as digest MUST first be verified against its SAD, and then the signature or seal on the SAID MAY be verified. This indirect verifiability (one or multiple levels of commitment via cryptographic digests) assumes that the cryptographic strength of the SAID digest is equivalent to the cryptographic strength of the signature used to sign it. To clarify, because all variants share the same top-level structure as the compact variant, then a signature on any variant MAY be used to verify the Issuer's commitment to any other variant either directly or indirectly, in whole or in part on a top-level section by top-level section basis. This cross-variant Issuer commitment verifiability is an essential property that supports Graduated Disclosure by the Disclosee of any or all variants, whether Full, Compact, Metadata, Partial, Selective etc.
 
-To elaborate, the SAID of a given variant is useful even when it is not the SAID of the variant the Issuer signed because, during Graduated Disclosure, the Discloser may choose to sign or seal that given variant to fulfill a given step in an IPEX Graduated Disclosure transaction. The Discloser thereby can make a verifiable disclosure in a given step of the SAD of a given variant that fulfills a commitment made in a prior step via its signature or seal on merely the SAID of the SAD of the variant so disclosed.
+To elaborate, the SAID of a given variant is useful even when it is not the SAID of the variant the Issuer signed because, during Graduated Disclosure, the Discloser MAY choose to sign or seal that given variant to fulfill a given step in an IPEX Graduated Disclosure transaction. The Discloser thereby can make a verifiable disclosure in a given step of the SAD of a given variant that fulfills a commitment made in a prior step via its signature or seal on merely the SAID of the SAD of the variant so disclosed.
 
-For example, the metadata variant of an ACDC will have a different SAID than the compact variant because some of the top-level field values may be empty in the metadata variant. One can think of the metadata variant as a partial manifest that only includes those top-level sections that the Discloser is committing to disclose in order to induce the Disclosee to agree to the contractual terms of use when disclosed. 
+For example, the metadata variant of an ACDC will have a different SAID than the compact variant because some of the top-level field values MAY be empty in the metadata variant. One can think of the metadata variant as a partial manifest that only includes those top-level sections that the Discloser is committing to disclose in order to induce the Disclosee to agree to the contractual terms of use when disclosed. 
 
-To elaborate, an IPEX transaction is between the Discloser and Disclosee, who both may make non-repudiable commitments to each other via signing or sealing variants of the ACDC to be disclosed. Typically, this means that the Discloser will eventually need to fulfill its commitment with proof of disclosure to the Disclosee. This proof may be satisfied either against the Discloser's signature or seal on the actual disclosed SAD or against the Discloser's signature or seal on the SAID of the actual disclosed SAD. In addition, the Disclosee will typically require proof of issuance via a non-repudiable signature or seal by the Issuer on a variant of the disclosed SAD that is verifiable (directly or indirectly) against the variant that is the disclosed SAD.
+To elaborate, an IPEX transaction is between the Discloser and Disclosee, who both SHOULD make non-repudiable commitments to each other via signing or sealing variants of the ACDC to be disclosed. Typically, this means that the Discloser will eventually need to fulfill its commitment with proof of disclosure to the Disclosee. This proof MAY be satisfied either against the Discloser's signature or seal on the actual disclosed SAD or against the Discloser's signature or seal on the SAID of the actual disclosed SAD. In addition, the Disclosee SHOULD typically require proof of issuance via a non-repudiable signature or seal by the Issuer on a variant of the disclosed SAD that is verifiable (directly or indirectly) against the variant that is the disclosed SAD.
 
 To summarize, when the Issuer commits to the composed Schema of an ACDC it is committing to all the variants so composed. As described above, the top-level field values in the compact variant enable verification against disclosure of any of the other Issuer committed variants because they all share the same top-level structure. This applies even to the metadata variant in spite of it only providing values for some top-level sections and not others. The verifiablity of a top-level section is separable.
 
-Consequently, the IPEX protocol must specify how a validator does validation of any variant in a Graduated Disclosure. To restate, there are two proofs that a Discloser must provide. The first is proof of issuance (PoI), and the second is proof of disclosure (PoD). In the former, the Discloser provides the variant via its SAD that was actually signed or seal (as SAD or SAID of SAD) by the Issuer in order for the Disclosee to verify authentic issuance via the signature on that variant.  In the latter, the Discloser must disclose the Issuer-enabled (via Schema composition) variant that the Discloser offered to disclose as part of the Graduated Disclosure process.
+Consequently, the IPEX protocol SHOULD specify how a validator does validation of any variant in a Graduated Disclosure. To restate, there are two proofs that a Discloser SHOULD provide. The first is proof of issuance (PoI), and the second is proof of disclosure (PoD). In the former, the Discloser provides the variant via its SAD that was actually signed or seal (as SAD or SAID of SAD) by the Issuer in order for the Disclosee to verify authentic issuance via the signature on that variant.  In the latter, the Discloser discloses the Issuer-enabled (via Schema composition) variant that the Discloser offered to disclose as part of the Graduated Disclosure process.
 
 
 #### IPEX Validation
 
 The goal is to define a validation process (set of rules) that works for all variants of an ACDC and for all types of Graduated Disclosure of that ACDC.
 
-For example, in the bulk issuance of an ACDC (see bulk issued ACDCs in the [Annex](#bulk-issued-private-acdcs)), the Issuer only signs or seals the blinded SAID of the SAD, which is the compact variant of the ACDC, not the SAD itself. This enables a Discloser to make a proof of inclusion of the ACDC in a bulk issuance set by unblinding the signature on the blinded SAID without leaking correlation to anything but the blinded SAID itself. To clarify, the Disclosee can verify the commitment to the SAID via set inclusion without disclosing any other information about the ACDC. Issuer signing or sealing of the SAID, not the SAD, also has the side benefit of minimizing the computation of large numbers of bulk-issued commitments.
+For example, in the bulk issuance of an ACDC (see bulk issued ACDCs in the [Annex](#bulk-issued-private-acdcs)), the Issuer only signs or seals the blinded SAID of the SAD, which is the compact variant of the ACDC, not the SAD itself. This enables a Discloser to make a proof of inclusion of the ACDC in a bulk issuance set by unblinding the signature on the blinded SAID without leaking correlation to anything but the blinded SAID itself. To clarify, the Disclosee can verify the commitment to the SAID via set inclusion without disclosing any other information about the ACDC. Issuer signing or sealing of the SAID, not the SAD, also has the benefit of minimizing the computation of large numbers of bulk-issued commitments.
 
 ##### Issuer Commitment Rules
 
-The Issuer must provide a signature or seal on the SAID of the most compact form variant defined by the Schema of the ACDC (see the "most compact form" algorithm above). 
+The Issuer MUST provide a signature or seal on the SAID of the most compact form variant defined by the Schema of the ACDC (see the "most compact form" algorithm above). 
 
 The different variants of an ACDC form a hash tree (using SAIDs).
 A commitment to the top-level SAID of the compact version of the ACDC is equivalent to a commitment to the hash tree root (trunk). This makes a verifiable commitment to all expansions of that tree.
 Different variants of an ACDC (SADs with SAIDs) correspond to different paths through the hash tree.
 The process of verifying a nested block SAD against its SAID is essentially verifying proof of inclusion of the branch of the hash tree that includes that nested block. This allows a single commitment (signature or seal) to provide PoI of the presentation of any Schema-authorized variants of the ACDC.
 
-An Issuer may provide signatures or seals on the SAIDs of other variants, as well as signatures or seals on the SADs of other variants.
+An Issuer SHOULD provide signatures or seals on the SAIDs of other variants and on the SADs of other variants.
 
 To summarize:
 
-Proof of Issuance (PoI) is provided by disclosing the SAID of the most compact variant and the verifiable commitment (signature or seal) by the Issuer on that SAID.
+Proof of Issuance (PoI) MAY be provided by disclosing the SAID of the most compact variant and the verifiable commitment (signature or seal) by the Issuer on that SAID.
 
-Proof of Disclosure (PoD) is provided by disclosing the SAD of the most compact variant and then recursively disclosing (expanding) the nested SADs of each of the blocks of the most compact variant as needed for the promised disclosure.
+Proof of Disclosure (PoD) MAY be provided by disclosing the SAD of the most compact variant and then recursively disclosing (expanding) the nested SADs of each of the blocks of the most compact variant as needed for the promised disclosure.
 
-Thus, for any disclosed variant of an ACDC, the Disclosee need only verify one PoI as defined above and may need to verify a specific PoD for a given disclosed variant as defined above.
+Thus, for any disclosed variant of an ACDC, the Disclosee MAY need only verify one PoI as defined above, and MAY need to verify a specific PoD for a given disclosed variant as defined above.
 
 ### Disclosure-specific (bespoke) issued ACDCs
 
-Chaining two or more ACDCs via edges enables disclosure-specific issuance of bespoke issued ACDCs. A given Discloser of an ACDC issued by some Issuer may want to augment the disclosure with additional contractual obligations or additional information sourced by the Discloser where those augmentations are specific to a given context, such as a specific Disclosee. A given Discloser issues its own bespoke ACDC referencing some other ACDC via an Edge. This means that the normal validation logic and tooling for a chained ACDC can be applied without complicating the presentation exchange logic. Furthermore, Attributes in other ACDCs pointed to by Edges in the bespoke ACDC may be addressed by Attributes in the bespoke ACDC using JSON Pointer or CESR-SAD-Path proof references that are relative to the node SAID in the Edge [[6]] [[ref: Proof_ID]].
+Chaining two or more ACDCs via edges enables disclosure-specific issuance of bespoke issued ACDCs. A given Discloser of an ACDC issued by some Issuer might want to augment the disclosure with additional contractual obligations or additional information sourced by the Discloser where those augmentations are specific to a given context, such as a specific Disclosee. A given Discloser issues its own bespoke ACDC referencing some other ACDC via an Edge. This means that the normal validation logic and tooling for a chained ACDC can be applied without complicating the presentation exchange logic. Furthermore, Attributes in other ACDCs pointed to by Edges in the bespoke ACDC MAY be addressed by Attributes in the bespoke ACDC using JSON Pointer or CESR-SAD-Path proof references that are relative to the node SAID in the Edge [[6]] [[ref: Proof_ID]].
 
-For example, this approach enables the bespoke ACDC to identify (name) the Disclosee directly as the Issuee of the bespoke ACDC. This enables contractual legal language in the Rules section of the bespoke ACDC that references the Issuee of that ACDC as a named party. Signing the agreement to the offer of that bespoke ACDC consummates a contract between the named Issuer and the named Issuee. This approach means that custom or bespoke presentations do not need additional complexity or extensions. Extensibility comes from reusing the tooling for issuing ACDCs to issue a bespoke or disclosure-specific ACDC. When the only purpose of the bespoke ACDC is to augment the contractual obligations associated with the disclosure, then the Attribute section, `a`, field value of the bespoke ACD may be empty, or it may include properties whose only purpose is to support the bespoke contractual language.
+For example, this approach enables the bespoke ACDC to identify (name) the Disclosee directly as the Issuee of the bespoke ACDC. This enables contractual legal language in the Rules section of the bespoke ACDC that references the Issuee of that ACDC as a named party. Signing the agreement to the offer of that bespoke ACDC consummates a contract between the named Issuer and the named Issuee. This approach means that custom or bespoke presentations do not need additional complexity or extensions. Extensibility comes from reusing the tooling for issuing ACDCs to issue a bespoke or disclosure-specific ACDC. When the only purpose of the bespoke ACDC is to augment the contractual obligations associated with the disclosure, then the Attribute section, `a`, field value of the bespoke ACD MAY be empty, or it MAY include properties whose only purpose is to support the bespoke contractual language.
 
-Similarly, this approach effectively enables a type of rich presentation or combined disclosure where multiple ACDCs may be referenced by edges in the bespoke ACDC that each contributes some Attribute(s) to the effective set of Attributes referenced in the bespoke ACDC. The bespoke ACDC enables the equivalent of a rich presentation without requiring any new tooling [[59]].
+Similarly, this approach effectively enables a type of rich presentation or combined disclosure where multiple ACDCs MAY be referenced by edges in the bespoke ACDC that each contributes some Attribute(s) to the effective set of Attributes referenced in the bespoke ACDC. The bespoke ACDC enables the equivalent of a rich presentation without requiring any new tooling [[59]].
 
 #### Example of a bespoke issued ACDC
 
@@ -2793,11 +2803,11 @@ Informative examples of fully-featured variants of ACDCs can be found in Annex C
 
 ### Overview
 
-A Transaction Event Log (TEL) is a hash-chained data structure of sealed transaction events that can be used to track the transaction states (typically those associated with one or more ACDCs). Events in the TEL are sealed (anchored) in a Key Event Log (KEL) using seals. A seal can be as simple as the event's SAID (cryptographic strength digest). A transaction event seal may also include the transaction event's sequence number to make it easier to look up and verify.  Because key events in a KEL are nonrepudiably signed by its Controller, the appearance of a transaction event seal provides a verifiable non-repudiable commitment to the transaction event by the KEL Controller. This makes TELs, which are thereby bound to KELs, also securely attributable to the KEL's controller.  This provides verifiable but decorrelatable extensibility to KEL semantics. Any number of transaction event types can be constructed for different applications that may be securely attributed without complicating KEL semantics. The seals need no semantics beyond their secure attributability to the AID of the KEL controller. The semantics of the transaction event's state may be hidden by the transaction event SAID, which in turn may be protected from rainbow table attack by a cryptographic strength UUID in the transaction event. Therefore, the transaction state, as given by a sequence of transaction events, can be either public or private, depending on how the transaction events are structured. Similar to ACDCs themselves, Graduated Disclosure mechanisms may be applied to transaction events. 
+A Transaction Event Log (TEL) is a hash-chained data structure of sealed transaction events that can be used to track the transaction states (typically those associated with one or more ACDCs). Events in the TEL are sealed (anchored) in a Key Event Log (KEL) using seals. A seal can be as simple as the event's SAID (cryptographic strength digest). A transaction event seal MAY also include the transaction event's sequence number to make it easier to look up and verify.  Because key events in a KEL are nonrepudiably signed by its Controller, the appearance of a transaction event seal provides a verifiable non-repudiable commitment to the transaction event by the KEL Controller. This makes TELs, which are thereby bound to KELs, also securely attributable to the KEL's controller.  This provides verifiable but decorrelatable extensibility to KEL semantics. Any number of transaction event types can be constructed for different applications that may be securely attributed without complicating KEL semantics. The seals need no semantics beyond their secure attributability to the AID of the KEL controller. The semantics of the transaction event's state may be hidden by the transaction event SAID, which in turn may be protected from rainbow table attack by a cryptographic strength UUID in the transaction event. Therefore, the transaction state, as given by a sequence of transaction events, can be either public or private, depending on how the transaction events are structured. Similar to ACDCs themselves, Graduated Disclosure mechanisms may be applied to transaction events. 
 
 Importantly, the process of sealing transaction events in a KEL binds the Key State at the sealing (anchoring) key event to the transaction state. This enables an extremely beneficial property of TELs; that is, the verifiability of transaction events in the TEL persists in spite of changes to Key States in the sealing KEL. In other words, the verifiability of transaction events persists in spite of changes in the Key State. To clarify, sealed transaction events remain verifiably bound to the Key State at the point of issuance of the sealing event. An example of a transaction state that benefits from this property is a TEL that tracks the issuance and revocation state of dynamically revocable ACDCs, i.e., a revocation registry.
 
-The transaction events shall be sealed (anchored or bound) in a KEL using transaction event seals, whose JSON representation is as follows.
+The transaction events MUST be sealed (anchored or bound) in a KEL using transaction event seals, whose JSON representation MUST be as follows.
 
 ```json
 {
@@ -2839,9 +2849,9 @@ In a blindable state Registry, usually, disclosure of the state by Discloser to
 
 The blind is derived from a secret salt shared between the Issuer and the designated Discloser. The current blind is deterministically derived from this salt and the sequence number of the transaction event. This is used to blind the state of the event. To elaborate, the hierarchically deterministic derivation path for the blind is the sequence number of the TEL event, which, combined with the salt, produces a universally unique salty nonce (UUID) to act as the blind. The Issuer publishes the transaction event with a blinded state so that a Validator can independently verify the Issuer's commitment to that state but without being able to determine the state via a seal in the Issuer's KEL with the SAID of that event. Only the Issuer can change the actual blinded state. Only the Issuer and Discloser have a copy of the secret salt, so only they can independently derive the current blind from the sequence number. Given the blind and a small finite number of possible values for the transaction state, the Discloser can verifiably discover and hence unblind the current transaction state from the published SAID of the current transaction event, its sequence number, and the shared secret salt. 
 
-The Issuer may provide an authenticated service endpoint for the Discloser to which the Discloser can make a signed request to update the blind.  Each new event published by the Issuer in the Registry shall increment the sequence number and hence the blinding factor but may or may not change the actual blinded state.  Because each updated event in the Registry has a new blinding factor regardless of an actual change of state or not, an observer cannot correlate state to event updates.
+The Issuer MAY provide an authenticated service endpoint for the Discloser to which the Discloser can make a signed request to update the blind.  Each new event published by the Issuer in the Registry MUST increment the sequence number and hence the blinding factor but MAY or MAY not change the actual blinded state.  Because each updated event in the Registry has a new blinding factor regardless of an actual change of state or not, an observer cannot correlate state to event updates.
 
-A blindabe state Registry may be used in an unblinded fashion. The Issuer could just publish the state unblinded. This makes is a public Registry. Consequently, a blindable state Registry is generic. It may be used in either a private or public manner.
+A blindabe state Registry MAY be used in an unblinded fashion. The Issuer could just publish the state unblinded. This makes is a public Registry. Consequently, a blindable state Registry is generic. It MAY be used in either a private or public manner.
 
 #### Message types
 
@@ -2852,7 +2862,7 @@ Blindable state registries have two types of events. These types are shown in th
 |`rip`| Registry Inception | registry initialization |
 |`upd`| Update | transaction event state update |
 
-In some cases, the usage of the registry may provide correlatable information, as would be the case where the first real transaction state is always the same or the final state results in the disuse of the Registry. In those cases, the Issuer may choose to define an empty (null) state and an empty (null) ACDC SAID as known placeholder values. The first transaction state update event in the Registry can, therefore, be published before any real ACDC has been created, to which it may be later applied. Disuse of the Registry can be hidden by continuing to update the blind to the state without changing the final state value for some time after the ACDC has been revoked or abandoned. 
+In some cases, the usage of the registry may provide correlatable information, as would be the case where the first real transaction state is always the same or the final state results in the disuse of the Registry. In those cases, the Issuer MAY choose to define an empty (null) state and an empty (null) ACDC SAID as known placeholder values. The first transaction state update event in the Registry can, therefore, be published before any real ACDC has been created, to which it may be later applied. Disuse of the Registry can be hidden by continuing to update the blind to the state without changing the final state value for some time after the ACDC has been revoked or abandoned. 
 
 
 #### Top-level fields
@@ -2874,54 +2884,54 @@ The reserved field labels for the top level of a blindable state registry transa
 
 #### Init event fields
 
-The fields for the Init, `rip` event , given by their labels, shall appear in the following order, `[v, t, d, u, i, s, dt]`. All are required. The value of the Message type, `t` field shall be `rip`. The value of the sequence number field, `s` shall be the hex encoded string for the integer 0. 
+The fields for the Init, `rip` event , given by their labels, MUST appear in the following order, `[v, t, d, u, i, s, dt]`. All are required. The value of the Message type, `t` field MUST be `rip`. The value of the sequence number field, `s` MUST be the hex encoded string for the integer 0. 
 
 #### Update event fields
 
-The fields for the Update, `upd` event , given by their labels, shall appear in the following order, `[v, t, d, r, s, p, dt, a]`. All are required. The value of the Message type, `t` field shall be `upd`. 
+The fields for the Update, `upd` event , given by their labels, MUST appear in the following order, `[v, t, d, r, s, p, dt, a]`. All are required. The value of the Message type, `t` field MUST be `upd`. 
 
 #### Field descriptions
 
 ##### Version String, `v` field
 
-The Version String, `v` field value uses the same format as an ACDC Version String {{see above}}. The protocol type shall be `ACDC`.
+The Version String, `v` field value uses the same format as an ACDC Version String {{see above}}. The protocol type MUST be `ACDC`.
 
 ##### Message type, `t` field
 
-The Message type, `t` field value shall be  one of the Message types in the table above. The Message types do not leak any state information. The first Message in some types of Registries such as an issuance/revocation Registry.
+The Message type, `t` field value MUST be  one of the Message types in the table above. The Message types do not leak any state information. The first Message in some types of Registries such as an issuance/revocation Registry.
 
 ##### SAID, `d` field
 
-The SAID, `d` field value shall be the SAID of its enclosing block. A transaction event's SAID enables a verifiable globally unique reference to that event.
+The SAID, `d` field value MUST be the SAID of its enclosing block. A transaction event's SAID enables a verifiable globally unique reference to that event.
 
 ##### UUID, `u` field
-The UUID, `u` field value shall be a cryptographic strength salty nonce with approximately 128 bits of entropy. The UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's SAID and knowledge of all possible state values, cannot discover the actual state in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's structure, possible state values, and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's state unless and until there has been a disclosure of that state.
+The UUID, `u` field value MUST be a cryptographic strength salty nonce with approximately 128 bits of entropy (nominally). The UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's SAID and knowledge of all possible state values, cannot discover the actual state in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's structure, possible state values, and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's state unless and until there has been a disclosure of that state.
 
 ##### Issuer, `i` field
 
-The Issuer, `i` field value shall be the AID of the Issuer. This removes any ambiguity about the semantics of a seal of a transaction event that appears in a KEL. When the KEL controller AID and Issuer AID are the same for a transaction event seal that appears in a given KEL, then the KEL Controller is making a commitment as Issuer to the transaction event. A transaction event seal that appears in a KEL with a different Controller AID is merely a nonrepudiable endorsement of the transaction state by some other party, not a duplicity-evident nonrepudiable commitment by the Issuer to the transaction state. This may appear to be redundant because the Issuer AID also appears in the ACDC. In a blinded state Registry, however, the ACDC SAID only appears in the blinded Attribute block likewise in a yet-to-be-disclosed private ACDC, the Issuer is also blinded, so a Registry observer that hosts a copy of the Registry that is not also a Disclosee of either the expanded transaction event and/or the associated ADCD would not be able to confirm that commitment and may thereby be subject to a DDoS attack without the presence of the Issuer, `i` field in the Registy initialization event's public top-level fields.
+The Issuer, `i` field value MUST be the AID of the Issuer. This removes any ambiguity about the semantics of a seal of a transaction event that appears in a KEL. When the KEL controller AID and Issuer AID are the same for a transaction event seal that appears in a given KEL, then the KEL Controller is making a commitment as Issuer to the transaction event. A transaction event seal that appears in a KEL with a different Controller AID is merely a nonrepudiable endorsement of the transaction state by some other party, not a duplicity-evident nonrepudiable commitment by the Issuer to the transaction state. This may appear to be redundant because the Issuer AID also appears in the ACDC. In a blinded state Registry, however, the ACDC SAID only appears in the blinded Attribute block likewise in a yet-to-be-disclosed private ACDC, the Issuer is also blinded, so a Registry observer that hosts a copy of the Registry that is not also a Disclosee of either the expanded transaction event and/or the associated ADCD would not be able to confirm that commitment and may thereby be subject to a DDoS attack without the presence of the Issuer, `i` field in the Registy initialization event's public top-level fields.
 
 ##### Registry SAID, `r` field
 
-The Registry SAID, `r` field value shall be the value of the SAID, `d` field of the Registry Inception, `rip` event. Because the Issuer, `i` field appears in the `rip` event, the Registry SAID, `r` field value cryptographically binds the Registry to the Issuer AID. The Registry SAID enables a verifiable globally unique reference to the Registry (TEL). Update events shall include the Registry SAID, `r` field so that they can be easily associated with the Registry (TEL). The ACDC managed by the Registry also includes a reference to the Registry in the ADCD's own Registry SAID, `rd` field, thereby binding the ACDC to the Registry. To clarify the value of the Registry SAID, `r` field in transaction events is the same value as the corresponding Registry SAID, `rd` field in the associated ACDC.
+The Registry SAID, `r` field value MUST be the value of the SAID, `d` field of the Registry Inception, `rip` event. Because the Issuer, `i` field appears in the `rip` event, the Registry SAID, `r` field value cryptographically binds the Registry to the Issuer AID. The Registry SAID enables a verifiable globally unique reference to the Registry (TEL). Update events MUST include the Registry SAID, `r` field so that they can be easily associated with the Registry (TEL). The ACDC managed by the Registry also includes a reference to the Registry in the ADCD's own Registry SAID, `rd` field, thereby binding the ACDC to the Registry. To clarify the value of the Registry SAID, `r` field in transaction events is the same value as the corresponding Registry SAID, `rd` field in the associated ACDC.
 
 ##### Sequence number, `s` field
 
-The sequence number, `s` field value shall be a hex-encoded string with no leading zeros of a zero-based strictly monotonically increasing integer. The first (zeroth) transaction event in a given Registry (TEL) shall have a sequence number of 0 or `0` hex.
+The sequence number, `s` field value MUST be a hex-encoded string with no leading zeros of a zero-based strictly monotonically increasing integer. The first (zeroth) transaction event in a given Registry (TEL) MUST have a sequence number of 0 or `0` hex.
 
 ##### Prior event SAID, `p` field
 
-The prior event SAID, `p` field value shall be the SAID, `d` field value of the immediately prior event in the TEL. The prior, `p` field backward chains together the events in a given TEL.
+The prior event SAID, `p` field value MUST be the SAID, `d` field value of the immediately prior event in the TEL. The prior, `p` field backward chains together the events in a given TEL.
 
 ##### Datetime, `dt` field
 
-The datetime, `dt` field value shall be the ISO-8601 datetime string with microseconds and UTC offset as per IETF RFC-3339. This shall be the datetime of the issuance of the transaction event relative to the clock of the issuer. An example datetime string in this format is as follows:
+The datetime, `dt` field value MUST be the ISO-8601 datetime string with microseconds and UTC offset as per IETF RFC-3339. This MUST be the datetime of the issuance of the transaction event relative to the clock of the issuer. An example datetime string in this format is as follows:
 
 `2020-08-22T17:50:09.988921+00:00`
 
 ##### Attribute, `a` field
 
-The Attribute, `a` field value shall be the SAID of the blinded Attribute block when used in a blinded (private) fashion. Alternatively, when used in an unblinded (public) fashion, the Attribute, `a` field value shall be either the fully expanded Attribute block (field map) or the SAID of the Attribute block but without its UUID, `u` field. See below for a description of the expanded Attribute block.
+The Attribute, `a` field value MUST be the SAID of the blinded Attribute block when used in a blinded (private) fashion. Alternatively, when used in an unblinded (public) fashion, the Attribute, `a` field value MUST be either the fully expanded Attribute block (field map) or the SAID of the Attribute block but without its UUID, `u` field. See below for a description of the expanded Attribute block.
 
 #### Expanded attribute block
 
@@ -2933,21 +2943,21 @@ The expanded Attribute block has the following fields:
 |u| UUID salty nonce blinding factor, random or HD generated |
 |ts| transaction state value string | 
 
-The fields shall appear in the following order `[d, u, ts]`. When used in private (blinded) mode, all are required. When used in public (unblinded) mode, the SAID, `d` field is optional, the UUID, `u` field is not allowed, the transaction state, `ts` field is required.
+The fields MUST appear in the following order `[d, u, ts]`. When used in private (blinded) mode, all are required. When used in public (unblinded) mode, the SAID, `d` field is OPTIONAL, the UUID, `u` field MUST NOT be present, the transaction state, `ts` field is REQUIRED.
 
 ##### SAID, `d` field
 
-The SAID, `d` field value shall be the SAID of its enclosing block. An Attribute section's SAID enables a verifiable globally unique reference to that state contained in the block but without necessarily disclosing that state.
+The SAID, `d` field value MUST be the SAID of its enclosing block. An Attribute section's SAID enables a verifiable globally unique reference to that state contained in the block but without necessarily disclosing that state.
 
 ##### UUID, `u` field
 
-The UUID, `u` field value shall be a cryptographic strength salty nonce with approximately 128 bits of entropy. The UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's SAID and knowledge of all possible state values, cannot discover the actual state in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's structure, possible state values, and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's state unless and until there has been a disclosure of that state.
+The UUID, `u` field value MUST be a cryptographic strength salty nonce with approximately 128 bits of entropy (nominally). The UUID, `u` field means that the block's SAID, `d` field value provides a secure cryptographic digest of the contents of the block [[48]]. An adversary, when given both the block's SAID and knowledge of all possible state values, cannot discover the actual state in a computationally feasible manner, such as a rainbow table attack [[30]] [[31]].  Therefore, the block's UUID, `u` field securely blinds the contents of the block via its SAID, `d` field notwithstanding knowledge of both the block's structure, possible state values, and SAID.  Moreover, a cryptographic commitment to that block's SAID, `d` field does not provide a fixed point of correlation to the block's state unless and until there has been a disclosure of that state.
 
 When the UUID, `u`, is derived from a shared secret salt and a public path such as the sequence number using a hierarchically deterministic derivation algorithm and given that the possible state values are finite and small, then any holder of the shared secret can derive the state given the public information in the top-level fields of the transaction event.
 
 ##### Transaction state, `ts` field
 
-The transaction state, `ts` field value shall be a string from a small finite set of strings that delimit the possible values of the transaction state for the Registry. For example, the state values for an issuance/revocation registry may be `issued` or `revoked`.
+The transaction state, `ts` field value MUST be a string from a small finite set of strings that delimit the possible values of the transaction state for the Registry. For example, the state values for an issuance/revocation registry may be `issued` or `revoked`.
 
 #### Private (blinded) state Registry example
 
@@ -2996,7 +3006,7 @@ The associated expanded Attribute block is as follows:
 
 Notice that the value of the attribute, `a` field in the transaction event, matches the value of the SAID, `d` field in the expanded attribute block. In this case, the value of the transaction state, the `ts` field, is just an empty string as a placeholder value. The transaction state may not yet correspond to a real ACDC.  The blind for this placeholder attribute block may be updated any number of times prior to its first use as the true state of a real ACDC. This makes the first use(s) of the registry uncorrelated to the actual issuance of the real ACDC. 
 
-Suppose that the Discloser has been given the shared secret salt from which the value of the blind, UUID, `u` field was generated. The Discloser can then download the published transaction event to get the sequence number, `s` field value. With that value and the shared secret salt, the Discloser can regenerate the blind UUID, `u` field value. The Discloser also knows the real ACDC that will be used for this Registry. Consequently, it knows that the value of the ACDC, SAID, `d` field must be either the empty string placeholder or the real ACDC SAID. The Discloser can now compute the SAID, `d` field value of the expanded Attribute block for either the empty placeholder value of the `ts` field or with one of the two possible state values, namely, `issued` or `revoked` for the `ts` field. This gives three possibilities. The Discloser tries each one until it finds the one that matches the published transaction event Attribute, `a` field value. The Discloser can then verify if the published value is still a placeholder or the real initial state.
+Suppose that the Discloser has been given the shared secret salt from which the value of the blind, UUID, `u` field was generated. The Discloser can then download the published transaction event to get the sequence number, `s` field value. With that value and the shared secret salt, the Discloser can regenerate the blind UUID, `u` field value. The Discloser also knows the real ACDC that will be used for this Registry. Consequently, it knows that the value of the ACDC, SAID, `d` field MUST be either the empty string placeholder or the real ACDC SAID. The Discloser can now compute the SAID, `d` field value of the expanded Attribute block for either the empty placeholder value of the `ts` field or with one of the two possible state values, namely, `issued` or `revoked` for the `ts` field. This gives three possibilities. The Discloser tries each one until it finds the one that matches the published transaction event Attribute, `a` field value. The Discloser can then verify if the published value is still a placeholder or the real initial state.
 
 Sometime later, the real ACDC is issued as indicated by its SAID, `d` field value, `ELMZ1H4zpq06UecHwzy-K9FpNoRxCJp2wIGM9u2Edk-P`. The value of the Issuer, `i` field of that ACDC will be the Issuer AID. The value of the registry SAID, `rd` field of that ACDC will be the registry SAID given by the value of the SAID, `d` field in the registry inception, `rip` event. This binds the ACDC to the Registry.
 
@@ -3190,9 +3200,9 @@ Sometime later, the ACDC is revoked with the publication by the Issuer of the fo
 
 ### Performance and Scalability
 
-The Compact Disclosure and distribute property graph fragment mechanisms in ACDC can be leveraged to enable high performance at scale. Simply using SAIDs and signed SAIDs of ACDCs in whole or in part enables compact but securely attributed and verifiable references to ACDCs to be employed anywhere performance is an issue. Only the SAID and its signature need be transmitted to verify secure attribution of the data represented by the SAID. Later receipt of the data may be verified against the SAID. The signature does not need to be re-verified because a signature on a SAID is making a unique (to within the cryptographic strength of the SAID) commitment to the data represented by the SAID. The actual detailed ACDC in whole or in part may then be cached or provided on-demand or just-in-time.
+The Compact Disclosure and distribute property graph fragment mechanisms in ACDC can be leveraged to enable high performance at scale. Simply using SAIDs and signed SAIDs of ACDCs in whole or in part enables compact but securely attributed and verifiable references to ACDCs to be employed anywhere performance is an issue. Only the SAID and its signature need be transmitted to verify secure attribution of the data represented by the SAID. Later receipt of the data MAY be verified against the SAID. The signature does not need to be re-verified because a signature on a SAID is making a unique (to within the cryptographic strength of the SAID) commitment to the data represented by the SAID. The actual detailed ACDC in whole or in part MAY then be cached or provided on-demand or just-in-time.
 
-Hierarchical decomposition of data into a distributed verifiable property graph, where each ACDC is a distributed graph fragment, enables performant reuse of data or more compactly performant reuse of SAIDs and their signatures. The metadata and attribute sections of each ACDC provide a node in the graph and the Edge section of each ACDC provides the Edges to that node. Higher-up nodes in the graph with many lower-level nodes need only be transmitted, verified, and cached once per every node or leaf in the branch not redundantly re-transmitted and re-verified for each node or leaf as is the case for document-based Verifiable Credentials where the whole equivalent of the branched (graph) structure must be contained in one document. This truly enables the bow-tie model popularized by Ricardian Contracts, not merely for contracts, but for all data authenticated, authorized, referenced, or conveyed by ACDCs.
+Hierarchical decomposition of data into a distributed verifiable property graph, where each ACDC is a distributed graph fragment, enables performant reuse of data or more compactly performant reuse of SAIDs and their signatures. The metadata and attribute sections of each ACDC provide a node in the graph and the Edge section of each ACDC provides the Edges to that node. Higher-up nodes in the graph with many lower-level nodes need only be transmitted, verified, and cached once per every node or leaf in the branch not redundantly re-transmitted and re-verified for each node or leaf as is the case for document-based Verifiable Credentials where the whole equivalent of the branched (graph) structure MUST be contained in one document. This truly enables the bow-tie model popularized by Ricardian Contracts, not merely for contracts, but for all data authenticated, authorized, referenced, or conveyed by ACDCs.
 
 [//]: # (Cryptographic Strength and Security {#sec:annexB .informative})
 
@@ -3200,7 +3210,7 @@ Hierarchical decomposition of data into a distributed verifiable property graph,
 
 #### Cryptographic Strength
 
-For crypto-systems with Perfect Security, the critical design parameter is the number of bits of entropy needed to resist any practical brute force attack. In other words, when a large random or pseudo-random number from a cryptographic strength pseudo-random number generator (CSPRNG) [@CSPRNG] expressed as a string of characters is used as a seed or private key to a cryptosystem with Perfect Security, the critical design parameter is determined by the amount of random entropy in that string needed to withstand a brute force attack. Any subsequent cryptographic operations must preserve that minimum level of cryptographic strength. In information theory, [@IThry][@ITPS] the entropy of a Message or string of characters is measured in bits. Another way of saying this is that the degree of randomness of a string of characters can be measured by the number of bits of entropy in that string.  Assuming conventional non-quantum computers, the conventional wisdom is that, for systems with Information- Theoretic or Perfect Security, the seed/key needs to have on the order of 128 bits (16 bytes, 32 hex characters) of entropy to practically withstand any brute force attack. A cryptographic quality random or pseudo-random number expressed as a string of characters will have essentially as many bits of entropy as the number of bits in the number. For other crypto systems such as digital signatures that do not have Perfect Security, the size of the seed/key may need to be much larger than 128 bits in order to maintain 128 bits of cryptographic strength.
+For crypto-systems with Perfect Security, the critical design parameter is the number of bits of entropy needed to resist any practical brute force attack. In other words, when a large random or pseudo-random number from a cryptographic strength pseudo-random number generator (CSPRNG) [@CSPRNG] expressed as a string of characters is used as a seed or private key to a cryptosystem with Perfect Security, the critical design parameter is determined by the amount of random entropy in that string needed to withstand a brute force attack. Any subsequent cryptographic operations MUST preserve that minimum level of cryptographic strength. In information theory, [@IThry][@ITPS] the entropy of a Message or string of characters is measured in bits. Another way of saying this is that the degree of randomness of a string of characters can be measured by the number of bits of entropy in that string.  Assuming conventional non-quantum computers, the conventional wisdom is that, for systems with Information- Theoretic or Perfect Security, the seed/key needs to have on the order of 128 bits (16 bytes, 32 hex characters) of entropy to practically withstand any brute force attack. A cryptographic quality random or pseudo-random number expressed as a string of characters will have essentially as many bits of entropy as the number of bits in the number. For other crypto systems such as digital signatures that do not have Perfect Security, the size of the seed/key may need to be much larger than 128 bits in order to maintain 128 bits of cryptographic strength.
 
 An N-bit long base-2 random number has 2<sup>N</sup> different possible values. Given that no other information is available to an attacker with Perfect Security, the attacker may need to try every possible value before finding the correct one. Thus, the number of attempts that the attacker would have to try maybe as much as 2<sup>N-1</sup>.  Given available computing power, one can show easily that 128 is a large enough N to make brute force attack computationally infeasible.
 
@@ -3225,7 +3235,7 @@ As explained previously in section 5, the primary difference between Partial Dis
 
 Recall that Partial Disclosure is an essential mechanism needed to support Chain-link Confidentiality [@CLC]. The Chain-link Confidentiality exchange offer requires Partial Disclosure, and Full Disclosure only happens after acceptance of the offer. Selective Disclosure, on the other hand, is an essential mechanism needed to unbundle in a correlation minimizing way a single commitment by an Issuer to a bundle of fields (i.e., a nested block or array of fields). This allows separating a "stew" of "ingredients" (Attributes) into its constituent ingredients (attributes) without correlating the constituents via the stew.
 
-ACDCs, inherently benefit from a minimally sufficient approach to Selective Disclosure that is simple enough to be universally implementable and adoptable. This does not preclude support for other more sophisticated but optional approaches. But the minimally sufficient approach should be universal so that at least one Selective Disclosure mechanism be made available in all ACDC implementations. To clarify, not all instances of an ACDC must employ the minimal Selective Sisclosure mechanisms as described herein but all ACDC implementations must support any instance of an ACDC that employs the minimal Selective Disclosure mechanisms as described above.
+ACDCs, inherently benefit from a minimally sufficient approach to Selective Disclosure that is simple enough to be universally implementable and adoptable. This does not preclude support for other more sophisticated but optional approaches. But the minimally sufficient approach should be universal so that at least one Selective Disclosure mechanism be made available in all ACDC implementations. To clarify, not all instances of an ACDC MUST employ the minimal Selective Disclosure mechanisms as described herein but all ACDC implementations MUST support any instance of an ACDC that employs the minimal Selective Disclosure mechanisms as described above.
 
 #### Tiered selective disclosure mechanisms
 
@@ -3247,7 +3257,7 @@ Selective Disclosure in combination with Partial Disclosure for Chain-link Confi
 
 #### Selectively disclosable attribute ACDC
 
-In a selectively disclosable attribute ACDC, the set of Attributes is provided as an array of blinded blocks. Each Attribute in the set has its own dedicated blinded block. Each block has its own SAID, `d`, field and UUID, `u`, field in addition to its attribute field or fields. When an Attribute block has more than one Attribute field, then the set of fields in that block are not independently selectively disclosable but must be disclosed together as a set. Notable is that the field labels of the selectively disclosable Attributes are also blinded because they only appear within the blinded block. This prevents unpermissioned correlation via contextualized variants of a field label that appear in a selectively disclosable block. For example, localized or internationalized variants where each variant's field label(s) each use a different language or some other context correlatable information in the field labels themselves.
+In a selectively disclosable attribute ACDC, the set of Attributes is provided as an array of blinded blocks. Each Attribute in the set has its own dedicated blinded block. Each block has its own SAID, `d`, field and UUID, `u`, field in addition to its attribute field or fields. When an Attribute block has more than one Attribute field, then the set of fields in that block are not independently selectively disclosable but MUST be disclosed together as a set. Notable is that the field labels of the selectively disclosable Attributes are also blinded because they only appear within the blinded block. This prevents unpermissioned correlation via contextualized variants of a field label that appear in a selectively disclosable block. For example, localized or internationalized variants where each variant's field label(s) each use a different language or some other context correlatable information in the field labels themselves.
 
 A selectively disclosable Attribute section appears at the top level using the field label `A`. This is distinct from the field label `a` for a non-selectively disclosable Attribute section. This makes clear (unambiguous) the semantics of the Attribute section's associated Schema. This also clearly reflects the fact that the value of a compact variant of selectively disclosable Attribute section is an aggregate, not a SAID. As described previously, the top-level selectively disclosable Attribute aggregate section, `A`, field value is an aggregate of cryptographic commitments used to make a commitment to a set (bundle) of selectively disclosable attributes. The derivation of its value depends on the type of Selective Disclosure mechanism employed. For example, the aggregate value could be the cryptographic digest of the concatenation of an ordered set of cryptographic digests, a Merkle tree root digest of an ordered set of cryptographic digests, or a cryptographic accumulator.
 
@@ -3451,7 +3461,7 @@ Moreover, because each a<sub>i</sub> element also makes a blinded commitment to
 
 Proof of inclusion in the list consists of checking the list for a matching value. A computationally efficient way to do this is to create a hash table or B-tree of the list and then check for inclusion via lookup in the hash table or B-tree.
 
-To protect against later forgery given a later compromise of the signing keys of the Issuer, the Issuer must anchor an issuance proof digest seal to the ACDC in its KEL. This seal binds the signing Key State to the issuance. There are two cases. In the first case, an issuance/revocation Registry is used. In the second case, an issuance/revocation Registry is not used.
+To protect against later forgery given a later compromise of the signing keys of the Issuer, the Issuer MUST anchor an issuance proof digest seal to the ACDC in its KEL. This seal binds the signing Key State to the issuance. There are two cases. In the first case, an issuance/revocation Registry is used. In the second case, an issuance/revocation Registry is not used.
 
 When the ACDC is registered using an issuance/revocation TEL, then the issuance proof seal digest is the SAID of the issuance (Inception) event in the ACDC's TEL entry. The issuance event in the TEL includes the SAID of the ACDC. This binds the ACDC to the issuance proof seal in the Issuer's KEL through the TEL entry.
 
@@ -3459,7 +3469,7 @@ When the ACDC is not registered using an issuance/revocation TEL, then the issua
 
 In either case, this issuance proof seal makes a verifiable binding between the issuance of the ACDC and the Key State of the Issuer at the time of issuance. Because aggregated value ‘A’ provided as the Attribute section, `A`, field, value is bound to the SAID of the ACDC which is also bound to the Key State via the issuance proof seal, the Attribute details of each attribute block are also bound to the Key state.
 
-The requirement of an anchored issuance proof seal means that the forger must first successfully publish in the KEL of the Issuer an inclusion proof digest seal bound to a forged ACDC. This makes any forgery attempt detectable. To elaborate, the only way to successfully publish such a seal is in a subsequent Interaction Event in a KEL that has not yet changed its Key State via a Rotation Event. Whereas any KEL that has changed its Key State via a Rotation must be forked before the Rotation. This makes the forgery attempt either both detectable and recoverable via Rotation in any KEL that has not yet changed its Key State or detectable as Duplicity in any KEL that has changed its Key State. In any event, the issuance proof seal ensures detectability of any later attempt at forgery using compromised keys.
+The requirement of an anchored issuance proof seal means that the forger must first successfully publish in the KEL of the Issuer an inclusion proof digest seal bound to a forged ACDC. This makes any forgery attempt detectable. To elaborate, the only way to successfully publish such a seal is in a subsequent Interaction Event in a KEL that has not yet changed its Key State via a Rotation Event. Whereas any KEL that has changed its Key State via a Rotation MUST be forked before the Rotation. This makes the forgery attempt either both detectable and recoverable via Rotation in any KEL that has not yet changed its Key State or detectable as Duplicity in any KEL that has changed its Key State. In any event, the issuance proof seal ensures detectability of any later attempt at forgery using compromised keys.
 
 Given that aggregate value ‘A’ appears as the compact value of the top-level Attribute section, `A`, field, the Selective Disclosure of the Attribute at index ‘j’ may be proven to the Disclosee with four items of information. These are:
 
@@ -3543,7 +3553,7 @@ Suppose there are ‘M’ ACDCs in a bulk issued set. Using zero-based indexing
 Let c<sub>k</sub> = v<sub>k</sub> + d<sub>k</sub> denote the blinding concatenation where ‘+’ is the infix concatenation Operator.
 Then the blinded digest, b<sub>k</sub>, is given by,
 b<sub>k</sub> = H(c<sub>k</sub>) = H(v<sub>k</sub> + d<sub>k</sub>),
-where H is the digest Operator. Blinding is performed by a digest of the concatenation of the binding factor, v<sub>k</sub>, with the SAID, d<sub>k</sub> instead of XORing the two. An XOR of two elements whose bit count is much greater than 2 is not vulnerable to a birthday table attack [[32]] [[31]] [[33]]. In order to XOR, however, the two must be of the same length. Different SAIDs MAY be of different lengths, however, and therefore, may require different length blinding factors. Because concatenation is length independent it is simpler to implement.
+where H is the digest Operator. Blinding is performed by a digest of the concatenation of the binding factor, v<sub>k</sub>, with the SAID, d<sub>k</sub> instead of XORing the two. An XOR of two elements whose bit count is much greater than 2 is not vulnerable to a birthday table attack [[32]] [[31]] [[33]]. In order to XOR, however, the two must be of the same length. Different SAIDs MAY be of different lengths, however, and therefore, may require different length blinding factors. Because concatenation is length-independent, it is simpler to implement.
 
 The aggregation of blinded digests, ‘B’, is given by,
 B = H(C(b<sub>k</sub> for all k in \{0, ..., M-1\})),
@@ -3559,13 +3569,13 @@ Proof of inclusion in the list of blinded digests consists of checking the list
 
 A proof of inclusion of an ACDC in a bulk-issued set requires disclosure of v<sub>k</sub> which is only disclosed after the Disclosee has accepted (agreed to) the terms of the rule section. Therefore, in the event the Disclosee declines to accept the terms of disclosure, then a presentation/disclosure of the compact version of the ACDC does not provide any point of correlation to any other SAID of any other ACDC from the bulk set that contributes to the aggregate ‘B’. In addition, because the other SAIDs are hidden by each b<sub>k</sub> inside the aggregate, ‘B’, even a presentation/disclosure of, \[b<sub>0</sub>, b<sub>1</sub>, ...., b<sub>M-1</sub>\] does not provide any point of correlation to the actual bulk-issued ACDC without disclosure of its v<sub></sub>. Indeed, if the Discloser uses a metadata version of the ACDC in its offer, then even its SAID is not disclosed until after acceptance of terms in the Rules section.
 
-To protect against later forgery given a later compromise of the signing keys of the Issuer, the Issuer must anchor an issuance proof seal to the ACDC in its KEL. This seal binds the signing Key State to the issuance. There are two cases. In the first case, an issuance/revocation Registry is used. In the second case, an issuance/revocation Registry is not used.
+To protect against later forgery, given a later compromise of the signing keys of the Issuer, the Issuer MUST anchor an issuance proof seal to the ACDC in its KEL. This seal binds the signing Key State to the issuance. There are two cases. In the first case, an issuance/revocation Registry is used. In the second case, an issuance/revocation Registry is not used.
 
 When the ACDC is registered using an issuance/revocation TEL, then the issuance proof seal digest is the SAID of the issuance (Inception) event in the ACDC's TEL entry. The issuance event in the TEL uses the aggregate value, ‘B’, as its identifier value. This binds the aggregate, ‘B’, to the issuance proof seal in the Issuer's KEL through the TEL.
 
 Recall that the usual purpose of a TEL is to provide a VDR  that enables dynamic revocation of an ACDC via a state of the TEL. A Verifier checks the state at the time of use to check if the associated ACDC has been revoked. The Issuer controls the state of the TEL. The Registry identifier, `rd`, field is used to identify the public Registry which usually provides a unique TEL entry for each ACDC. Typically, the identifier of each TEL entry is the SAID of the TEL's Inception Event which is a digest of the event's contents which include the SAID of the ACDC. In the bulk issuance case, however, the TEL's Inception Event contents include the aggregate, ‘B’, instead of the SAID of a given ACDC. Recall that the goal is to generate an aggregate value that enables an Issuee to selectively disclose one ACDC in a bulk-issued set without leaking the other members of the set to unpermissioned parties (2nd or 3rd).
 
-Using the aggregate, ‘B’ of blinded ACDC SAIDs as the TEL Registry entry identifier allows all members of the bulk-issued set to share the same TEL without any 3rd party being able to discover which TEL any ACDC is using in an unpermissioned provable way. Moreover, a 2nd party may not discover in an unpermissioned way any other ACDCs from the bulk-issued set not specifically disclosed to that 2nd party. In order to prove to which TEL a specific bulk issued ACDC belongs, the full inclusion proof must be disclosed.
+Using the aggregate, ‘B’ of blinded ACDC SAIDs as the TEL Registry entry identifier allows all members of the bulk-issued set to share the same TEL without any 3rd party being able to discover which TEL any ACDC is using in an unpermissioned provable way. Moreover, a 2nd party may not discover in an unpermissioned way any other ACDCs from the bulk-issued set not specifically disclosed to that 2nd party. In order to prove to which TEL a specific bulk issued ACDC belongs, the full inclusion proof MUST be disclosed.
 
 When the ACDC is not registered using an issuance/revocation TEL then the issuance proof seal digest is the aggregate, ‘B’, itself.
 
@@ -3576,7 +3586,7 @@ A Discloser may make a basic provable non-repudiable Selective Disclosure of a g
 - The ACDC in compact form (at index ‘k’) where ‘d<sub>k</sub> as the value of its top-level SAID, `d`, field.
 - The blinding factor, v<sub>k</sub> from which b<sub>k</sub> = H(v<sub>k</sub> + d<sub>k</sub>) may be computed.
 - The list of all blinded SAIDs, \[b<sub>0</sub>, b<sub>1</sub>, ...., b<sub>M-1</sub>\] that includes b<sub>k</sub>.
-- A reference to the anchoring seal in the Issuer's KEL or TEL that references the aggregate ‘B’. The event that references the seal or the TEL event that references ‘B’ must be signed by the issuer so the signature on either event itself is sufficient to prove authorized issuance.
+- A reference to the anchoring seal in the Issuer's KEL or TEL that references the aggregate ‘B’. The event that references the seal or the TEL event that references ‘B’ MUST be signed by the issuer so the signature on either event itself is sufficient to prove authorized issuance.
 
 The aggregate ‘B’ is a point of unpermissioned correlation but not permissioned correlation. To remove ‘B’ as a point of unpermissioned correlation requires using independent TEL bulk-issued ACDCs described in the section so named below.
 
@@ -3590,7 +3600,7 @@ A Disclosee may then verify the disclosure by:
 
 The last 3 steps that culminate with verifying the anchoring seal also require verifying the Key state of the Issuer at the time of issuance, this may require additional verification steps as per the KERI, PTEL, and CESR-Proof protocols.
 
-The requirement of an anchored issuance proof seal of the aggregate ‘B’ means that the forger must first successfully publish in the KEL of the Issuer an inclusion proof digest seal bound to a set of forged bulk-issued ACDCs. This makes any forgery attempt detectable. To elaborate, the only way to successfully publish such a seal is in a subsequent Interaction Event in a KEL that has not yet changed its Key State via a Rotation Event. Whereas any KEL that has changed its Key State via a Rotation must be forked before the Rotation. This makes the forgery attempt either both detectable and recoverable via Rotation in any KEL that has not yet changed its Key State or detectable as Duplicity in any KEL that has changed its Key state. In any event, the issuance proof seal makes any later attempt at forgery using compromised keys detectable.
+The requirement of an anchored issuance proof seal of the aggregate ‘B’ means that the forger must first successfully publish in the KEL of the Issuer an inclusion proof digest seal bound to a set of forged bulk-issued ACDCs. This makes any forgery attempt detectable. To elaborate, the only way to successfully publish such a seal is in a subsequent Interaction Event in a KEL that has not yet changed its Key State via a Rotation Event. Whereas any KEL that has changed its Key State via a Rotation MUST be forked before the Rotation. This makes the forgery attempt either both detectable and recoverable via Rotation in any KEL that has not yet changed its Key State or detectable as Duplicity in any KEL that has changed its Key state. In any event, the issuance proof seal makes any later attempt at forgery using compromised keys detectable.
 
 #### Inclusion proof via Merkle tree 
 
@@ -3610,7 +3620,7 @@ Recall that the purpose of using the aggregate ‘B’ for a bulk-issued set fro
 
 However, in some applications where Chain-link Confidentiality does not sufficiently deter malicious provable correlation by Disclosees (2nd party Verifiers), an Issuee may benefit from using ACDC with independent TELs or independent aggregates ‘B’ but that are still bulk-issued.
 
-In this case, the bulk issuance process must be augmented so that each uniquely identified copy of the ACDC gets its own TEL entry (or equivalently its own aggregate ‘B’) in the registry. Each Disclosee (Verifier) of a full presentation/disclosure of a given copy of the ACDC only receives proof of one uniquely identified TEL and cannot provably correlate the TEL state of one presentation to any other presentation because the ACDC SAID, the TEL identifier, and the signature of the Issuer on each aggregate ‘B’ will be different for each copy. There is, therefore, no point of provable correlation, permissioned or otherwise. For example, this approach could be modulated by having a set of smaller bulk issued sets that are more contextualized than one large bulk-issued set.
+In this case, the bulk issuance process MUST be augmented so that each uniquely identified copy of the ACDC gets its own TEL entry (or equivalently its own aggregate ‘B’) in the registry. Each Disclosee (Verifier) of a full presentation/disclosure of a given copy of the ACDC only receives proof of one uniquely identified TEL and cannot provably correlate the TEL state of one presentation to any other presentation because the ACDC SAID, the TEL identifier, and the signature of the Issuer on each aggregate ‘B’ will be different for each copy. There is, therefore, no point of provable correlation, permissioned or otherwise. For example, this approach could be modulated by having a set of smaller bulk issued sets that are more contextualized than one large bulk-issued set.
 
 The obvious drawbacks of this approach (independent unique TELs for each private ACDC) are that the size of the Registry database increases as a multiple of the number of copies of each bulk-issued ACDC and every time an Issuer must change the TEL state of a given set of copies it must change the state of multiple TELs in the Registry. This imposes both a storage and computation burden on the Registry. The primary advantage of this approach, however, is that each copy of a private ACDC has a uniquely identified TEL. This minimizes unpermissioned 3rd party exploitation via provable correlation of TEL identifiers even with colluding 2nd party Verifiers. They are limited to statistical correlation techniques.
 
@@ -3626,7 +3636,7 @@ In essence, an ACDC is really just a verifiable property graph fragment of an ex
 
 ### ACDC protocol Message types
 
-CESR support for the ACDC protocol includes conveying sections of an ACDC as CESR-compatible messages (packets). These messages can be part of a CESR stream or part of the attachment group to an ACDC. This is useful for sending the ACDC in its compact form and then attaching the section details as individual message packets. This enables one to cache sections so that they do not have to be transmitted repeatedly or reuse sections that are the same for multiple ACDC instances, which is often the case for the schema and rule sections. An ACDC message itself may have as an option a message type field. This allows CESR native versions of ACDCs. The default is that absent a message type field, an ACDC protocol message given by the version string field is an ACDC. All other message types shall have the message type field. The following table provides all the message types (ilks) for the ACDC protocol. The message type (ilk) field label is `t` and shall appear at the top-level immediately following the version string, `v` field.
+CESR support for the ACDC protocol includes conveying sections of an ACDC as CESR-compatible messages (packets). These messages can be part of a CESR stream or part of the attachment group to an ACDC. This is useful for sending the ACDC in its compact form and then attaching the section details as individual message packets. This enables one to cache sections so that they do not have to be transmitted repeatedly or reuse sections that are the same for multiple ACDC instances, which is often the case for the schema and rule sections. An ACDC message itself may have as an option a message type field. This allows CESR native versions of ACDCs. The default is that absent a message type field, an ACDC protocol message given by the version string field is an ACDC. All other message types MUST have the message type field. The following table provides all the message types (ilks) for the ACDC protocol. The message type (ilk) field label is `t` and MUST appear at the top-level immediately following the version string, `v` field.
 
 #### Message type table
 
@@ -3647,7 +3657,7 @@ CESR support for the ACDC protocol includes conveying sections of an ACDC as CES
 
 #### ACDC Message with Message type field
 
-The following table defines the top-level fields in an ACDC with a Message type field and their order of appearance. Some fields are optional, but all fields that appear shall appear in this order, `[v, t, d, u, i, s, a, A, e, r]`.
+The following table defines the top-level fields in an ACDC with a Message type field and their order of appearance. Some fields are optional, but all fields that appear MUST appear in this order, `[v, t, d, u, i, s, a, A, e, r]`.
 
 | Label | Title | Description |
 |:-:|:--|:--|
@@ -3684,7 +3694,7 @@ Python dict of compact ACDC with message type, `t` field.
 
 #### ACDC message as top-level field map in CESR native format
 
-When an ACDC message appears in CESR native format as a top-level field it shall use either of the CESR count codes, `-G##` or  `-0G#####` at the top-level. The top-level fields (labels and values) that appear shall appear in the following order: `[ v, t, d, u, i, rd, s, a, A, e, r]`. The required fields are `[v, t, d, i, s]`. The rules for the appearance of optional fields are the same as those defined above for the other serialization kinds. The major difference here is that the Version field value is a CESR primitive that provides the protocol type and the version. It does not provide a serialization kind or length. This is already indicated by the count code, `-G##` or  `-0G#####`.
+When an ACDC message appears in CESR native format as a top-level field it MUST use either of the CESR count codes, `-G##` or  `-0G#####` at the top-level. The top-level fields (labels and values) that appear MUST appear in the following order: `[ v, t, d, u, i, rd, s, a, A, e, r]`. The required fields are `[v, t, d, i, s]`. The rules for the appearance of optional fields are the same as those defined above for the other serialization kinds. The major difference here is that the Version field value is a CESR primitive that provides the protocol type and the version. It does not provide a serialization kind or length. This is already indicated by the count code, `-G##` or  `-0G#####`.
 
 #####  Compact Private ACDC with top-level field map in CESR native format
 
@@ -3717,7 +3727,7 @@ For clarity the first column provides the equivalent label value for the other s
 |`e`| Edge| Either the SAID of a block of Edges or the block itself.|
 |`r`| Rule | Either the SAID a block of Rules or the block itself. |
 
-Each section Message must have Version String, `v`, Message type, `t`,  and SAID, `d` fields in that order. The value of the SAID, `d` field is the said of the Message block itself not the SAID of the embedded section field value. The embedded section block's SAID, `d` field should match the section field value in the associated compact ACDC.
+Each section Message MUST have Version String, `v`, Message type, `t`,  and SAID, `d` fields in that order. The value of the SAID, `d` field is the said of the Message block itself not the SAID of the embedded section field value. The embedded section block's SAID, `d` field MUST match the section field value in the associated compact ACDC.
 
 The remaining field is the appropriate section field for the Message type, as follows: