Check an absence claim

Presence is proven by one example. Absence needs an exhaustive check. A wrong "it is gone" hides itself - nothing ever contradicts it - so it costs far more than a wrong "it is here".

Steps

1. State the claim exactly: "X does not exist", "X is dead", "there is no backup of X".
2. Search beyond the first spelling:
   • other names, abbreviations, and casings; the concept, not just the identifier;
   • callers through indirection: string-based dispatch, config, cron, schedulers, reflection;
   • moved, not deleted: git log -S '<name>' and git log --diff-filter=D --name-only;
   • places your tools do not show: ignored files, other branches, the deployed host, other repos.
3. Read past the title. A file named after a retired thing can document live things further down.
4. Suspect your instruments. "The dashboard does not show it" is a fact about the dashboard.
5. Report one of exactly three verdicts, with every place searched:
   • present - with file:line;
   • absent - only if the search above was exhaustive;
   • could not confirm either way - the honest answer when it was not.

If you found an observation gap

A real thing with no visible confirmation is a defect in itself: the next person will make the same misjudgment. Note it, and propose making the thing visible.

Background: harness-kit principles/absence-judgment.md.