Two different absences

NONE_FOUND means the reviewed corpus contains no evidence that meets a defined category and threshold. It is a statement about the corpus. UNKNOWN means available evidence does not establish either the positive or the negative proposition. It is a statement about knowledge.

Intentional examples

Independent validation is NONE_FOUND for the systems in this coverage release because no evidence satisfies the purpose, maturity, and independence rules. That does not mean the systems fail. Simbian's public constraint model is UNKNOWN beyond the vendor statement that selected firewall actions occur without human intervention. That does not mean controls are absent.

Google Detection Engineering Agent availability is UNKNOWN because reviewed public sources conflict on the preview phase. The projection does not silently choose public preview, and it does not translate the conflict into a negative capability claim.

Why buyers should care

Procurement teams can turn NONE_FOUND into a diligence request for an external test or customer reference. Engineering teams can turn UNKNOWN into a product-specific question about permissions, rollback, model routing, or deployment scope. Keeping the terms separate prevents missing evidence from becoming unsupported certainty.