3.1.1.11.1.3 Claim Source
Claims have two sources of values:
AD: Active Directory is the default claim source.
Certificate: Certificate sourced claims originate from the strings provided to the GetClaimsForPrincipal procedure (section 3.1.1.11.2.1) and are single-valued Boolean claims.
Constructed claims are generated dynamically according to a claim-specific algorithm, but are still considered to have AD as their source.