diff --git a/context/playtest-tracker.md b/context/playtest-tracker.md
index f867f09..ba6dfcf 100644
--- a/context/playtest-tracker.md
+++ b/context/playtest-tracker.md
@@ -72,10 +72,17 @@ know if it happens again". If the thread already answers it, do not ask again.
   routinely superseded, retracted, or already fixed by comment 4. Triaging 53 tickets from
   threads moved a third of the statuses and dropped P1 from 5 to 2. See
   [[reconstruction-gotchas]] for the general form of this mistake.
-- **Undated tester rows are historical.** Only rows explicitly prefixed with a date (`8/14 - `)
-  came from that session. Reading undated carried-forward rows as fresh evidence produced a false
-  "still crashing after the fix" report on #170 that had to be retracted across seven tickets.
-  Ask testers to date entries.
+- **DATE EVERY TESTER ENTRY: `M/D - ` at the front of each line.** The build is cut per session,
+  so the date implies the build — which is what makes a Pass or Fail interpretable at all.
+  Entries carried over from before this convention are marked **`(undated)`**, meaning
+  *provenance unknown — do not treat as fresh evidence*. That marker is deliberate: the sheet was
+  seeded from earlier tracking and nobody can now say which rows are original, so stamping them
+  all with the session date would manufacture precision. Reading undated rows as fresh already
+  produced a false "still crashing after the fix" claim on #170 that had to be retracted across
+  seven tickets — #170's row carries the same three timestamps and players as its own 2026-08-12
+  body, and whether that is a copy-forward or a genuine recurrence is STILL UNRESOLVED.
+  One entry per line, each with its own stamp; comment cells grow over time and undated text
+  running together is unreadable within two sessions.
 - **Never write `DONE` on OPEN.** A row that is done belongs on CLOSED; a `DONE` on the open page
   is a contradiction that confuses everyone reading it.
 - **Merge duplicates to one row per ticket** — linking loose reports to existing tickets creates