diff --git a/tools/outcome-coverage.mjs b/tools/outcome-coverage.mjs
index baea19e..7ae10db 100644
--- a/tools/outcome-coverage.mjs
+++ b/tools/outcome-coverage.mjs
@@ -37,6 +37,17 @@ export const BASELINE = path.join(ROOT, "tools", "outcome-coverage-baseline.json
 
 /* ------------------------------------------------------------------ the beats */
 
+/* ONE PATTERN FOR BOTH HALVES OF THIS FILE, and it agrees with check-scenarios' `tagsIn`
+   deliberately. R-291 measured the two apart: `tagsIn` was widened to tolerate case and
+   spacing around the colon, this file's strict half was not, and `[cus: Spot — x]` was then
+   READ by one guard and reported unparseable by the other. The build failed, which is the
+   safe direction, but it failed saying the tag could not be read while another guard had
+   just read it. Widened to match; `beatLikeIn` below still refuses `[CUS Spot]` and
+   `[CUS= Spot]`, which neither strict reader accepts, so the canary keeps its teeth.
+   check-behaviour asserts the two readers agree — that assertion is the thing that must
+   not be deleted, not this comment. */
+const TAG = /\[\s*CUS\s*:\s*([^\]—]+?)\s*(?:—|\])/gi;
+
 const indentOf = l => { const m = l.match(/^(\s*)(?:[-*]|\d+\.)\s/); return m ? m[1].length : null; };
 const isHeading = l => /^#{1,6}\s/.test(l);
 
@@ -55,7 +66,7 @@ export function beatsIn(text) {
     if (/^\s*```/.test(l)) { inFence = !inFence; return; }
     if (inFence) return;
     const quoted = /^\s*>/.test(l);
-    for (const m of l.matchAll(/\[CUS:\s*([^\]—]+?)\s*(?:—|\])/g)) {
+    for (const m of l.matchAll(TAG)) {
       if (quoted) { out.push({ line: i + 1, skill: m[1].trim(), quoted: true }); continue; }
       let owner = i;
       for (let j = i; j >= 0; j--) {
@@ -84,7 +95,7 @@ export function beatsIn(text) {
 /** A `[CUS …]` that this reader cannot parse is worse than no tag: somebody thinks it is
     one. Asymmetric with beatsIn on purpose — R-286's castLikeIn, same reasoning. */
 export function beatLikeIn(text) {
-  const good = [...text.matchAll(/\[CUS:\s*([^\]—]+?)\s*(?:—|\])/g)].map(m => [m.index, m.index + m[0].length]);
+  const good = [...text.matchAll(TAG)].map(m => [m.index, m.index + m[0].length]);
   return [...text.matchAll(/\[\s*CUS\b[^\]]*\]/gi)]
     .filter(m => !good.some(([a, b]) => m.index >= a && m.index < b))
     .map(m => ({ raw: m[0].slice(0, 70), line: text.slice(0, m.index).split("\n").length }));