Original text:
4.1. If the presentation of the SD-JWT VC includes a Key Binding JWT, the <del> Key Binding JWT MUST adhere to the rules defined in Section 5.3 of I- </del>  D.ietf-oauth-selective-disclosure-jwt. The Key Binding JWT MAY include additional claims which, when not

Reviewer comments:
Remove the requirement to insert a .well-known part for vct URLs , ,
Dr. Fett, PhD: >Gentlemen, Some feedback I received (on top of the comments we already got in the issuers) makes me second-guess the choice to use a .well-known URL for the type metadata documents. In fact, RFC 5785 tells us that .well-known is mainly to be used for site-wide information or information about a specific host. that it will be used to make site-wide policy information and other metadata available directly (if sufficiently concise), or provide references to other URIs that provide such metadata. Brian Campbell, B.A.: >That feedback seems not wrong to me. We've got probably a lot of somewhat questionable uses of .well-known but type metadata is maybe less well suited than most. And less needed. >It could just point to the json document. Or we make up some convention. Or something with uri templates.
Relevant related issues: , ,
I believe that lifting the restriction is not preventing the use of .well-known; IMO there are two approaches provide the full link signal that the metadata is under the well-known However, metadata owner must be aware of the responsibility to take care of the versioning. As mentioned in , should there be a requirement to either use hash links or protect the remote content via vct#digest? Dr. Horvat, PhD
Maybe I'm missing something, but the change in PR should mostly solve this, I think. It now requires to provide the full URL to the metadata. (If someone wants to provide it under .well-known, that is their choice, but doesn't influence the requester at all). For versioning I filed a . Not sure about making #digest mandatory, but we should also discuss this separately.
digest mandatory, but we should also discuss this separately. -> if it's an external resource, it should be defined how it is protected
URL Is defining that if vct is an https:// it should check the metadata under the well known (at least the 2nd part of the text reads like this: Many registries are, and will be accessible via URLs, hence the metadata type is expressed via an URL; Adding or maintaining a .well-known might not fit in the existing API designs. Also note that .well-known has well-known issues with multi-tenancy. Most use cases will delegate the hosting of the information to registries. Also Questions: if schema is https, should the full URL be provided? (no ambiguity with .well-known, you can host schema on github, ...) metadata retrieval category re-consideration: 1) Fetch vct from a remote source: a) URL: HTTPS schema -> full URL that points to a schema b) URN: domain-defined URN that MUST be understood by the wallet; The URN method defines how to map the URN to URL and retrieve the data 2) Fetch vct the metadata locally a) local cache b) Signature (signed or unsigned header); Whether or not metadata is shared in the (un)protected header is defined by the signature format, hence out of scope of this document. 2b: point to consider for the OID4VP: should there be a flag: "archival mode" or similar, that would flag that the wallet needs to provide all the referenced content in an unprotected JWS header?
removes the requirement to insert .well-known (discussion in )
Type Metadata introduced new well-known URI /.well-known/vct/ in "6.3.1. From a URL in the vct" , but this is not reflected in appendix-A.3 Well-Known URI Registry. Additionally, using in sentence "Metadata can be retrieved from the URL URL, i.e., by inserting /.well-known/vct after the authority part of the URL." seems to me a little bit confusing as type is considered to refer to whole URI. Maybe use or (to include also query and fragment URI components)?
Thank you and yes, the registration request is missing and needs to be added. And that sentence could also be improved.
Although the use of .well-known for type metadata is being reconsidered
Current text: Since well-known only applies to HTTPS URLs, we should limit the section to HTTPS URLs although other URLs would be still possible, e.g., . Additionally, also the in is probably not correct since the type refers to the value itself which would not make sense to the full value here which would also include the scheme for instance. I suggest we update the title to "From an HTTPS URL in the claim" and update the language to something like this:

Revised text:
4.1. If the presentation of the SD-JWT VC includes a Key Binding JWT, the  <ins> Key Binding JWT MUST adhere to the rules defined in Section 4.3 of I- </ins> D.ietf-oauth-selective-disclosure-jwt. The Key Binding JWT MAY include additional claims which, when not