Existing Wording: Note that since [FHIR resources do not need to be served through the FHIR API], the absolute URL might not end with the logical id of the resource (Resource.id), but if the fullUrl does look like a RESTful server URL (e.g. meets the regex, then it SHALL end with the Resource.id.

Proposed Wording: Note that since [FHIR resources do not need to be served through the FHIR API], the absolute URL might be a urn rather than a RESTful url and not be a proper RESTful URL containing the logical id of the resource (Resource.id). However, if the fullUrl is structured as a RESTful server URL (e.g. meets the regex), then the 'id' portion of the fullUrl following the final '/' SHALL match the Resource.id.

Comment:

Merely ending with the id isn't sufficient. Need to explain what the other options are for the id

Summary:

Improve comment on resource-id/url matching