Trim Cot Leakage

Trimming Chain-of-Thought Leakage

Chain-of-thought leakage is prose whose vantage is the authoring session rather than the repository: it cites artifacts only that session could see, narrates the change instead of the state, or argues with a reviewer who has left. The fix is never deletion alone when a passage carries factual clauses — restate each so it stands on its own, then delete the transcript around it; a passage carrying none is deleted outright. Before editing, enumerate the complete proposition: preserve each actor, action, condition, timing, modality, negative guarantee, exception, ownership, side effect, failure mode, and consequence. It is guidance, not a script.

The one test

For every suspect passage ask: could a reader with no access to any session transcript, PR thread, or uncommitted draft resolve every reference and verify every claim? If no, restate the surviving facts and delete the rest. If yes, it is not leakage — but a resolvable change story on a current-state surface (README, docs, skill body) is still change narration and belongs in a commit, PR, or Agent Note.

Taxonomy

1. Dead design-session citations — (decision 7), (audit C2), design §4.7, phase labels (T4, W3). If the decision has a committed owner, cite it by name and path; otherwise delete the citation and restate its factual clause.
2. Stack and PR vantage — "a later PR in this stack", "this PR adds", "the previous commit". State the shipped mechanism; deferred work becomes a TODO marker or an issue reference.
3. Change narration and version stamps — "used to", "no longer", "the old X", and indexical stamps ("v1", "this cut", "today"). State the present behavior; a fixed regression becomes a present-tense counterfactual ("without X, Y happens"), never repo history.
4. Review choreography — "rejected in review", "the reviewer confirmed", draft ordinals ("v5 of this note"). Keep the surviving decision and rationale as plain fact.
5. Reviewer-addressed justification — "the cast is safe — it simply…", "this is correct because…". State the invariant that makes the code or rule safe, or delete the comment.
6. Restatement and derivation transcripts — control-flow narration ("first we X, then we Y"), proofs of obvious branches. Delete; keep only a non-obvious contract.
7. Hedges and planning residue — "probably fine for now", "should be enough", deferrals with no marker. Promote to TODO/FIXME or restate as the actual bound.
8. Authoring-language slips — untranslated fragments in prose whose language is otherwise English, or the reverse in a .zh.md counterpart. Translate or delete.

What is not leakage

Unaided citation passes fail in both directions by deleting durable references and keeping dead ones. Apply these keep rules as written:

• Issue references — #1470, TODO(name):, "issue #N owns the follow-up" resolve at HEAD; keep them on any surface, including READMEs. Do not relocate them to Agent Notes.
• Merged-PR and issue citations inside Agent Notes and postmortems — sanctioned evidence per the documentation standard's change-story routing.
• Suppression justifications — lint-disable -- reason clauses, coverage-ignore reasons, and empty-catch explanations are required prose; fix a false reason, never delete it.
• Counterfactual-present regression pins — "without X, Y happens", "a naive X would…".
• Measured bounds — "(measured: …)" calibrating a constant; the provenance word "measured" is load-bearing.
• Runtime old/new states — "the old connection drains before the new one accepts" is runtime lifecycle, not change history.
• Historical stage names inside a note's change-story sections — "the first cut shipped X" is current-state-safe there; indexical stamps ("this cut") stay banned everywhere.
• External references that resolve outside the repo by design — standards sections (RFC 9110 §10.1.5), design-artifact names (a Figma frame). The §-ban covers uncommitted internal drafts, not external standards or committed docs that own their §-numbering.
• Project voice and genre forms — "we" as project voice; a note's Alternatives-considered section.

Workflow

1. Require an explicit scope. Never touch vendor/, frozen archived notes, or recorded fixtures and snapshots — recorded model output and sealed history keep their original voice.
2. Audit read-only first: run the recall batteries, then judge every hit semantically. The batteries over-match by design and under-match by nature — also read the densest prose in scope without a pattern in hand.
3. Fix owner-first: for a bilingual pair, update the counterpart; for a generated or manifest-listed surface, fix the source.
4. Before deleting anything, enumerate the passage's propositions and check the overcorrection traps.
5. Verify: re-run the batteries expecting only sanctioned keeps, confirm every remaining citation resolves, and run your repository's documentation checks for touched docs.