BFM-decomp/rules/L2.md

# L2 — lever-removal-is-a-tracked-series
id: L2 · group: - · status: active · tags: legacy,memory · origin: legacy memory lever-removal-is-a-tracked-series.md · added: 2026-09-29

Drew (2026-09-09, mid-Phase-36): the pins and compiler hints are not just work to finish — **their count over time is a
deliverable**. Keep `docs/levers.md` current after **every task that changes the count**, with
`tools/lever_progress.py --snapshot "<task>"` (appends a milestone row to `docs/lever-progress.tsv` and re-renders the
document's generated block; `--check` refuses a stale series). Mirror the story-relevant numbers into
`phase-ends/CURRENT_PHASE.md` as the phase goes, so the retrospective is built from the record and not from memory.

Four audiences, all named by Drew: the **post-100% chart**, the **project story**, the **wiki** (a Levers page), and the
**`decomp-architect/` package** — which needs the taxonomy plus an answer to *"what should we have done from day one to stop
this creeping up on us post-100%, or is leaving it to a post-100% cleanup actually optimal?"*

**Why:** the only phase that ever counts the levers is the phase that removes them, so if the series is not captured while
the work happens it cannot be reconstructed afterwards — a census is a moment. The measured answer so far (P36): **38% of
the class A/B population came off with no understanding at all** (strip, compile, compare), which is the evidence for the
day-one rule *ban the silence, not the lever* — a lever is allowed but is a marked, ledgered, published debt from the first
bank, with a one-compile bank-time trial that would have refused a third of them where the context was still hot.

**How to apply:** at every task close run the census then `lever_progress --snapshot`; keep §5 of `docs/levers.md` (the
prevent-vs-defer argument) written from the generated numbers, never typed; feed each new rung/recipe and each measured
yield into §4. Related: [[matching-cookbook]] (§454 carries the mechanism), [[decomp-accelerator-ledger]],
[[phaseend-verbosity-for-the-retrospective]], [[project-endgame-deliverables]].