Current evidence type of id_document is defined as:
id_document: Verification based on any kind of government issued identity document.
This is assuming that an identity document is presented for verification, however in some instances an ID document itself is not used, the user provides a unique reference number (like a civil registration number) and the OP gets the identity data directly from an official registrar to use as the basis of the proof. In many cases an ID document is merely a method of exchanging the information from a state register, its not the source of authority in itself.
Suggest this is instead
id_evidence: An official identity document or identity register.