2026.10.13
Document reference rules and SSOT for Codex
Adding new documents leaves old fragments in partial-match search results. An observation about reference rules and a single source of truth.
In several recent tasks, I thought Codex had behaved strangely or encountered a bug, but it had actually stopped after misinterpreting an old reference document. This made me realize how forgetting to update documents after a specification change can lead to unexpected behavior.
Adding a new document does not stop partial-match searches from finding old documents. A fragment retrieved by search does not reveal whether it is current without reading its contents. Even after reading it, without rules for deciding which information to follow, the fragment may be taken at face value. That is what I observed this time.
I think two things matter: establishing document rules and arranging for old documents not to be referenced. This also reminded me of the importance of SSOT: avoid managing duplicate documents and keep the overall structure easy to understand. These are observations from my own work at the time of the posts.
Related: Check for old information when debugging AI behavior, Review duplicate instructions and leftovers when improving Skills