Authentic Source
An Authentic Source is a repository or system, run by a public sector body or private entity, that holds and provides attributes about a person, organisation, or object, and is considered the primary, authoritative record for that attribute.
A national trade register is an Authentic Source for company registration data; a tax authority is an Authentic Source for a VAT number. An Attestation Provider that issues a credential based on an attribute is not itself the Authentic Source unless it also runs the underlying register: the two roles are often the same organisation, but the ARF keeps them conceptually separate. For a KYB or KYC check, going back to the Authentic Source rather than a document the counterparty presents is what removes the need to re-verify data that hasn't changed.