Inspection document (2.1, 2.2, 3.1, 3.2)
The four types of material inspection document defined by EN 10204, distinguished by who performed the inspection and how independent they were.
The distinction that matters most is between a 2.2 — results from non-specific inspection, not necessarily the material delivered — and a 3.1, which reports specific inspection on the products actually supplied, validated by an inspector independent of manufacturing.
Contracts specify 3.1 routinely. Deliveries arrive with 2.2 more often than anyone would like, and the gap surfaces at dossier compilation when replacing the material is no longer an option.