The register keeps changing after the book is fixed in print. Each entry below was added to this row in the order shown.
RETIERED 11 August 2026 under D-028 against EVIDENCE_PROTOCOL's six-level source hierarchy. The previous value was an ad hoc quality score on an undocumented scale. Tier now records SOURCE TYPE only; how far this project has checked the document is the Status column. Previous value: tier 1.