Notes that rot

Claim: the model tends to explain its code by pointing at its own work-session — “step 6,” “round 2,” “the earlier fix” — instead of at the reason. Those pointers mean something for one afternoon and nothing forever after. The words in the comment are usually fine; the reference is the rot.

The incident

I suspected that months of writing under strict style rules had left the codebase full of bad, over-worked prose. I had it measured: 1296 comments graded. The prose was mostly clean — and there were zero of the invented metaphors I had spent weeks fighting. But one defect dominated, 85% of every failure: comments that cited a session label. “(item 6, round A.)” “(the round-C report.)” Notes pointing at a conversation no future reader would ever have.

The comment beside the label almost always already carried the real reason. The label added nothing and pointed nowhere.

The rule

A comment or a doc should point at something a future reader can actually reach: the decision record, the reason itself, the ticket. Never at the session that produced it. If the reason is worth noting, state the reason. Enforce it cheaply — these labels come in a few shapes (“item N,” “round X”), so a grep in the merge check catches them before they land.

Prior art

Verdict: PARTIAL, and the closest to unfound of the set. Adjacent categories exist: an LLM-generated-comment taxonomy (arXiv:2607.01867) has “PastFuture” / “Meta” buckets that could house session labels but doesn’t isolate them; “TODO: Fix the Mess Gemini Created” (arXiv:2601.07786) studies comments admitting AI authorship; “context rot” for stale AI config artifacts (arXiv:2606.09090); and pre-AI comment-rot work (comment-vs-code drift). None names the specific defect — a comment whose prose is fine but whose pointer to the generating session (“item 6, round A”) is dead — nor reports a measurement isolating it (~85% of comment failures against near-zero invented metaphors), nor the merge-time grep for a few label shapes. Mechanism + measurement + fix appears original to this write-up as far as the sweep found. Distinct from banning invented words: there the words are the problem; here the words are fine and the reference is dead.