Move normative DID method specification statements about equivalentId and canonicalId into this spec #911
Description
Currently DID Resolution defines equivalentId and canonicalId as an optional part of the DID Document Metadata object returned in a resolution request.
In these definitions there are a number of normative requirements placed on the DID Method:
Each equivalentId DID value MUST be produced by, and a form of, the same DID method as the id property value
A conforming DID method specification MUST guarantee that each equivalentId value is logically equivalent to the id property value.
equivalentId is a much stronger form of equivalence than alsoKnownAs because the equivalence MUST be guaranteed by the governing DID method
A canonicalId value MUST be produced by, and a form of, the same DID method as the id property value.
A conforming DID method specification MUST guarantee that the canonicalId value is logically equivalent to the id property value.
During the DID Resolution test suite discussion, it was suggested that theses statements would be better suited to the DID spec. Probably under https://www.w3.org/TR/did/upcoming/#method-operations.
If the WG agrees that this is a class 3 change, we need to figure out how to add these statements and then tidy up the DID resolution specification.