Please ping me (Nick) if you have any questions about what to document here. I think it makes sense to include the 'encryptMetadata' keyword in the same DOCS ticket.
- Can be present anywhere in the schema, including top-level.
- Suggest starting with a new "translateEncryptionKeywords" method at the[ entry point in the parser|https://github.com/mongodb/mongo/blob/83a494cb0a1afca5cfaaf9d29eeb8a2ce1e02264/src/mongo/db/matcher/schema/json_schema_parser.cpp#L1355].
- Resulting match expression should contain the new $_internalSchemaBinDataSubType expression.
- This ticket should only implement the parsing required for mongod to understand the new keywords, no mongocryptd/FLE specific logic. For now, require that the "encrypt" argument is an empty object.