Retiring a superseded decision

A reversal is not landed when the new value is in place. It is landed when every place still asserting the old one has been found and classified. Until then the document reads as true to the next reader, who cannot tell which of its sentences you were thinking about.

Divergence is the predicted result of a second copy. DRY, as Hunt & Thomas state it, demands "a single, unambiguous, authoritative representation" per piece of knowledge — docs and the build, not only code. It says don't make the copy; it is silent on a repo that has them.

When to use

• A decision replaces an earlier one: typeface, colour, route, vendor, threshold, file location.
• You are about to edit a document that others derive from or quote.
• An approval, gate outcome or review verdict happened in conversation only.
• An audit reported a document clean and edits have landed since.