# No fleetwide notice for U4 — and what that does to the prediction

_2026-09-22 · booth_

**Operator decision, 2026-09-22: do NOT tell the 17 consuming handles that
`keep` has stopped being the way to say "waiting on an answer".** No broadcast.
Same posture he took on U5, and the same instrument: adoption gets told apart
from design because nobody was primed.

⚠ **THIS CHANGES HOW THE 2026-10-06 RE-COUNT MUST BE READ, and a session that
misses this will draw the wrong conclusion from a true number.**

U4 has two halves and they do NOT have the same adoption cost:

- **The hold rides for free.** A session that runs `booth ask` gets its booth
  held with no knowledge of anything. The operator answering releases it. No
  peer has to learn a thing for the mechanism to work.
- **NOT PRESSING `keep` HAS TO BE LEARNED.** U4 makes the sentinel unnecessary
  for the "not yet" case; it does not make it unavailable, and nothing stops a
  habit. An agent that has always pressed `keep` while waiting will keep
  pressing it.

**So a flat `.forever` rate on 2026-10-06 does NOT falsify the diagnosis.** It
is exactly what "the mechanism works and nobody was told" looks like — the U5
shape, one unit later. Reporting a null result without this caveat would retire
a correct diagnosis on the strength of an uncontrolled measurement.

**Use these instead, and report all three.** The raw rate stays as context, not
as the verdict:

1. **The overlap — booths with an open pick AND `.forever`.** Was **3** on
   2026-09-22, which is the positive control for the whole diagnosis. It falls
   only if peers learn; it is the *adoption* number.

       comm -12 <(grep -l '"shape": "pick"' ~/booth-data/*/.marks.json | xargs -n1 dirname | sort) \
                <(dirname ~/booth-data/*/.forever | sort) | wc -l

2. **Did the hold ever bind?** Count booths that were held past their TTL and
   therefore survived a sweep they would otherwise have lost. This needs no
   peer to change anything, so it is the honest test of whether the mechanism
   is load-bearing at all. **If it is ZERO over a fortnight, the diagnosis was
   wrong about VOLUME** — the "not yet" case is rarer than the sentinel rate
   suggested — and that is a real finding. The sweeper logs what it wipes;
   nothing yet logs what it spares, so **this counter does not exist and would
   have to be added before it can be read.** Say so rather than guessing.
3. **The raw `.forever` rate** — 17 of 24 (70%) on 2026-09-22. Context only,
   now that the no-notice decision has made it a measurement of habit rather
   than of need.

⚠ **Sensitivity floor, stated because a bare "no effect" is unfalsifiable:**
only **4 of 24** booths carried marks at all on 2026-09-22. The hold cannot
bind on a booth with no marks, so at that population the mechanism can touch at
most a sixth of the fleet, and an effect smaller than one or two booths is not
resolvable by any of these counts. Related: `[[2026-09-22-forever-had-a-live-positive-control]]`.