The hierarchical ranking of corroboration sources by their authority weight in AI entity resolution systems. Tier 1: Peer-reviewed academic sources, major news outlets, government authorities, established encyclopedic sources. Tier 2: Industry analysts, trade publications, authoritative industry directories, credentialed expert publications. Tier 3: General business publications, company-controlled content, social media. Not all sources are equal: a single tier-1 source carries more corroboration weight than ten tier-3 sources. Corroboration campaigns must prioritize tier-1 and tier-2 placement to move entity confidence thresholds.