Code change:
array instead of retrieving the respective Type Metadata elsewhere as follows: <ins> 6.4. An SD-JWT VC type can extend another type.  The extended type is identified by the URI in the property.  Consumers MUST retrieve and process Type Metadata for the extended type before processing the Type Metadata for the extending type. The extended type MAY itself extend another type.  This can be used to create a chain or hierarchy of types.  The security considerations described in circular-extends apply in order to avoid problems with circular dependencies. 6.5. 6.5.1. Schemas for Verifiable Credentials are contained in the or retrieved via the Type Metadata parameters (as defined in type-metadata-format).  A schema MUST be represented by a JSON Schema document according to draft version 2020-12 JSON.SCHEMA.2020-12 or above. The schema of a Verifiable Credential MUST include all properties that are required by this specification and MUST NOT override their cardinality, JSON data type, or semantic intent. The following is a non-normative example of a JSON Schema document for the example in vc-sd-jwt-example requiring the presence of the claim in an SD-JWT VC presentation: Note that and are always required by this specification. 6.5.2. If a or property is present, a Consumer MUST validate the JSON document resulting from the SD-JWT verification algorithm (as defined in Section 8 of I-D.ietf-oauth-selective-disclosure-jwt) against the JSON Schema document provided by the or property. If an property is present, the schema of the extended type MUST also be validated in the same manner.  This process includes validating all subsequent extended types recursively until a type is encountered that does not contain an property in its Type Metadata.  Each schema in this chain MUST be evaluated for a specific Verifiable Credential. If the schema validation fails for any of the types in the chain, the Consumer MUST reject the Verifiable Credential. The following is a non-normative example of a result JSON document after executing the SD-JWT verification algorithm that is validated against the JSON Schema document in the example provided in schema- definition: Note, the example above does not contain any , , or claims. </ins> 7. Both the <del> claim in the SD-JWT VC and various URIs in the metadata document MAY </del> <ins> claim in the SD-JWT VC and the various URIs in the Type Metadata MAY </ins> be accompanied by a respective claim suffixed with , in particular:

Related discussion:
text: Two approvals, merging now.
The text currently says: It must by the Issuer's choice to support either x5c, jwt-vc metadata or both, this is also how HAIP defines it. Extending this thought, the Verifier has no means of understanding what the issuer supports, given that may be an HTTPS URI but no support is avaiblable for jwt-vc metadata. This is because is the best indicator but in Section 5 only described as RECOMMENDED. Proposal is that the Issuer may chose this and that the presence of in SD-JWT VC indicates jwt-vc metadata.
This is from HAIP: By following the HAIP text, I don't understand how an issuer can support both options in an SD-JWT VC? Can you give an example? Furthermore, DNS name is not a URI and strictly speaking is this not allowed as per SD-JWT VC where has to be a URI. For that reason, SD-JWT VC says that the value needs to be encoded using the dns URI scheme. I'm not saying SD-JWT VC should not be changed in that regards because I do see some potential for improvement and I think as well that an issuer might want to support both and that needs to be addressed. We should discuss ways how this can be achieved. But I don't think is appropriate for this to control whether a verifier fetches well-known or not. I would assume that a verifier will likely know which issuer ( value) to trust and also know if the issuer is part of some trust framework that supports well-known. If not, the verifier will have to try in the same way as they try other well-knowns. I don't see the need to connect the presence of with the presence of well-known if this is what you suggested. Furthermore, I believe your specific use cases is already supported by: using an HTTPS URI for the value hosting a well-known for that URI including a x5c header with a URI SAN entry that matches the value
I don't think using to indicate whether well-known is supported is a good solution. I don't think we need this indication for the reasons pointed out above.