Having issue indexing entry with symbols/ special characters

[db101097]

I have a Document instance set up like this
store = new Document({ worker: false, document: { id: "id", index: [ { field: "abbreviation", tokenize: "strict", optimize: true, }, ], store: true, }, });

I added to that document using the add function, passing in

{ id: 0, abbreviation: '#', expansions: [ { plainText: '£', deltas: undefined, weight: 1, idInSearchableIndex: 0, contentType: 'Plain' } ] }

However the id does not show up in the register nor can I search for it. It does work if I add a letter to abbreviation for example
{ id: 0, abbreviation: 'a#', expansions: [ { plainText: '£', deltas: undefined, weight: 1, idInSearchableIndex: 0, contentType: 'Plain' } ] }
Any idea what's going wrong or what I need to add to the config to get this to work ?