There are field in the DocumentReference profile that are difficult to implement for the CCD profile and vice versa. For example, formatCode really only applies to non-CDA documents. Our EHR wouldn't generate a formatCode for PDFs or HTMLs. Identifiers also are not persisted when generating CCDs.

I propose to remove mustSupport for CCD DocumentReferences:

• identifier
• Category
• Author (a person doesn't generate the document. Organization makes sense here)
• Custodian
• Content.attachment.data
• Context.encounter (These are person level documents)

I propose to remove mustSupport for ClinicalNotes

• Custodian
• content.format
• Content.attachment.data