AI system certainty threshold for entity identification. Binary behavior: above threshold = full citation, below = hedging/omission/displacement. Build through corroboration (minimum 5 tier-1/2 sources), structured data consistency (schema.org completeness), and temporal depth (multi-year signal history). Test through parametric recall probes and citation coverage measurement. Critical: confidence doesn’t degrade gradually — it holds then drops discontinuously when maintenance lapses.