diff --git a/docs/re/METHOD.md b/docs/re/METHOD.md
index 58128948..fc19112e 100644
--- a/docs/re/METHOD.md
+++ b/docs/re/METHOD.md
@@ -646,6 +646,20 @@ agent's loop prompt, i.e. nowhere durable. See [`README.md`](README.md) for the
   so check a replacement as hard as you checked the thing it replaces, and hardest
   when the edit is *about* checking.
 
+* 📌 **Work completed and never indexed is the same failure as a refutation
+  argued and never indexed — one level up.** `sylpheed-port` found a milestone whose
+  gate had been met "for a very long time" with no gate record: the work existed,
+  the artifact existed, the *record* did not. ✅ Audited the Decoder's objective for
+  the same shape and it is **clean** — all ten questions cite a result page, every
+  `data/` and `captures/` path those pages cite resolves, and the files are
+  substantive rather than stubs
+  ([`data/mission-gate-audit.txt`](data/mission-gate-audit.txt)).
+  ⚠️ **A clean audit is worth exactly its checks**, so state them: this tests that
+  **cited** files **exist** and carry content. It does not test that the data
+  supports the claim, and **it cannot see data a page should have cited and did
+  not** — a page citing nothing would have passed as "0 missing". Existence and
+  substance, never sufficiency.
+
 ## Runtime / emulator
 
 * **Look at the PNG** — and check its dimensions.
diff --git a/docs/re/data/mission-gate-audit.txt b/docs/re/data/mission-gate-audit.txt
new file mode 100644
index 00000000..0dee108a
--- /dev/null
+++ b/docs/re/data/mission-gate-audit.txt
@@ -0,0 +1,49 @@
+# Are MISSION's gates MET and RECORDED, both halves? 2026-08-30.
+#
+# sylpheed-port found P0 complete-but-unindexed -- the work existed, the artifact
+# existed, the gate record did not -- and named it as the argued-versus-indexed
+# split one level up from the refutation register. This is the same audit on the
+# Decoder's objective.
+#
+# MISSION's gate: "a written docs/re/ result with the evidence, and REFERENCE DATA
+# COMMITTED ALONGSIDE IT". Two halves, and all ten questions read ✅ answered.
+#
+# HALF ONE -- every Q cites a docs/re/ result. All ten do:
+#   Q1  ui-keyframe-time-unit.md + ui-keyframe-record-layout.md
+#   Q2  ui-title-build-map.md
+#   Q3  structures/ui-paint-order-key.md + ui-paint-order-derived-check.md
+#   Q4  menu-navigation-semantics.md          Q5  menu-navigation-semantics.md
+#   Q6  boot-config-and-gamepart-registry.md  Q7  screen-transitions.md
+#   Q8  menu-audio-cues.md                    Q9  movie-binding.md
+#   Q10 structures/bgm-two-stems.md + slb-bank-header-not-a-wave.md
+#
+# HALF TWO -- reference data committed alongside. Every data/ and captures/ path
+# cited by those pages was resolved against the tree:
+#
+#   ui-keyframe-time-unit.md              3 cited, 0 missing
+#   ui-title-build-map.md                11 cited, 0 missing
+#   structures/ui-paint-order-key.md     11 cited, 0 missing
+#   menu-navigation-semantics.md         11 cited, 0 missing
+#   boot-config-and-gamepart-registry.md  3 cited, 0 missing
+#   screen-transitions.md                 4 cited, 0 missing
+#   menu-audio-cues.md                    2 cited, 0 missing
+#   movie-binding.md                      2 cited, 0 missing
+#   structures/bgm-two-stems.md           1 cited, 0 missing
+#
+# And spot-checked for substance rather than mere existence, since the gate's
+# PURPOSE is that the port can work without a disc:
+#   splash-ramp-check.txt          1 197 B   15 numeric lines
+#   fade-envelope-menu-to-title    2 373 B   34
+#   fade-four-transitions.txt     20 737 B  198
+#   se-cue-runtime-offsets.txt     2 258 B   17
+#   se-ui-cues.txt                 7 134 B  324
+#   bgm-wave-census.txt            3 369 B   33
+#
+# ✅ CLEAN. Both halves present for all ten, and unlike the port's P0 they were
+# also INDEXED -- HANDOFF's status table cites the page, the page cites the data.
+#
+# ⚠️ REACH, because a clean audit is only worth its checks. This tests that CITED
+# files EXIST and are non-trivial. It does NOT test that the data supports the
+# claim, and it cannot see data a page SHOULD have cited and did not. A page
+# citing nothing would have passed as "0 missing"; none did, but the check would
+# not have caught it. Existence and substance, not sufficiency.