Docs rot in a predictable way, and the fix is a single distinction every project applies the same way: some docs describe how things are now and must be swept when things change; others record a moment in time and must be left alone. Getting this right keeps a large restructure from either stranding stale guidance or rewriting history. The canonical copy is in the repository at hub/standards/docs-lifecycle.md.

The two kinds of doc

• Current-state — architecture, systems deep-dives, READMEs, the AI-context (CLAUDE.md), reference guides, status.md. Sweep on every rename or removal, in the same change — fix names, paths, and claims to match reality now.
• Dated history — session logs, changelog / version.md, decision records, process reports. Leave intact. These describe a moment; “fixing” them is rewriting history.
• Removed-feature docs — a guide for a feature that’s gone. Banner, don’t delete — a note at the top preserves the knowledge while flagging it non-current.

The rules

• Sweep current-state docs on every rename/move/removal, in the same change.
• Never edit dated history to “correct” it — corrections go in new current-state docs.
• Banner removed features; don’t silently delete their docs.
• Prefer paths a checker can verify, so drift is mechanically catchable (the repo-hygiene link gate catches the rest).
• One source of truth per fact; link, don’t duplicate.