An act of a human or an automated rule confirming, or un-confirming, a Knowledge Item's accuracy at a point in time.
One or more per Knowledge Item, accumulating over its lifetime
Full history retained — the sequence of verifications is itself evidence of a content item's trustworthiness over time
Only the control-bearing entities were modelled for lifecycle. Defensible as a starting point, but it does leave the entity model uneven, and this is incompleteness rather than a finding.