Provenance within SKUA potentially means three distinct things:

Which SAC did it come from? This is audit-trail-type provenance, discussed in ClaimProvenanceHistory

Did the apparent author actually make this claim? This is linked to 'which SAC' and discussed in ClaimValidity, but a distinct issue, in that it's probably an issue concerning signing/security rather than bookkeeping/history

What evidence did they have for this claim? This is a rhetorical/argumentational issue -- that's a minor industry, but that means there are vocabularies or ontologies knocking about (refs?) which we can re-use