Procurement documents - Public & with Restricted access

Part of the procurement documents may be freely accessible while others may have, most likely for confidentiality reason, a restricted access.

Expected information is:

• "Documents URL": this could be mapped to cac:CallForTenderDocumentReference/cac:Attachment/cac:ExternalReference/cbc:URI
• "Documents Official Language" and "Documents Unofficial Language": cf. UBL-209
• "Documents Restricted Justification (code)": to be clarified
• "Documents Restricted URL": could be marked as cac:Attachment/cac:ExternalReference/cbc:URI

DocumentReference only allows for one Attachment and I couldn't find a way to identify at the Attachment level a Document with Restricted access and the associated justification.

I understand documents with restricted access as part of the CallForTenderDocument and would expect to find reference to these documents in this element, however, they may also be seen as Call ForTenders Supporting/Additional Documents as they generally convey further detailed information.

What would you suggest:

• Have a new element at the TenderingTerms level of type CallForTendersSupportingDocumentReference?
• allow for multiple attachments in the CallForTenderDocumentReference and provide a way to specify the restricted access and the reason for it?
• another option?

How to best address "Document restricted Justification (Code)":

• use the DocumentTypeCode element of the DocumentReference, categorizing documents based on their access and associated justification?
• have one (or more) new dedicated element(s) at Attachment or DocumentReference level?