diff --git a/.github/scripts/linked-issue.js b/.github/scripts/linked-issue.js
index 26626fa..4be0f19 100644
--- a/.github/scripts/linked-issue.js
+++ b/.github/scripts/linked-issue.js
@@ -1,6 +1,12 @@
 // Matches the issue keys of our Linear teams, in any case.
 const KEY = /\b(?:[KW][MPS]|[FINRSZ][AELMNP][FLQRSTWX])-\d+\b/i;
 
+// A body line such as "No-Issue: typo fix" explains why the PR has no issue.
+const NO_ISSUE = /^No-Issue:[ \t]*(\S.*)$/im;
+
+// HTML comments, such as PR template hints, do not render. An unclosed one hides the rest.
+const HTML_COMMENT = /<!--[\s\S]*?(?:-->|$)/g;
+
 // join() turns a null body into an empty string.
 function hasLinearKey(title, body, branch) {
   return KEY.test([title, body, branch].join('\n'));
@@ -12,4 +18,10 @@ function isBot(user) {
   return user.type === 'Bot';
 }
 
-module.exports = { hasLinearKey, isBot };
+// Returns the No-Issue reason from the body, or null if there is none.
+function noIssueReason(body) {
+  const match = NO_ISSUE.exec((body ?? '').replace(HTML_COMMENT, ''));
+  return match ? match[1].trim() : null;
+}
+
+module.exports = { hasLinearKey, isBot, noIssueReason };
diff --git a/.github/scripts/linked-issue.test.js b/.github/scripts/linked-issue.test.js
index f7bd0db..7af6d23 100644
--- a/.github/scripts/linked-issue.test.js
+++ b/.github/scripts/linked-issue.test.js
@@ -1,5 +1,5 @@
 const assert = require('node:assert/strict');
-const { hasLinearKey, isBot } = require('./linked-issue.js');
+const { hasLinearKey, isBot, noIssueReason } = require('./linked-issue.js');
 
 assert.ok(hasLinearKey('Fix login', '', 'user/ws-42'), 'lowercase branch key');
 assert.ok(hasLinearKey('Fix login', 'Fixes WS-123', 'user/fix-login'), 'key in body');
@@ -16,4 +16,15 @@ for (const s of ['SHA-256', 'UTF-8', 'ISO-8601', 'CVE-2024-1234', 'RFC-9110', 'T
 assert.ok(isBot({ login: 'dependabot[bot]', type: 'Bot' }), 'Dependabot is a bot');
 assert.ok(isBot({ login: 'nps-schema-doc-generator[bot]', type: 'Bot' }), 'app bot');
 assert.ok(!isBot({ login: 'someone', type: 'User' }), 'a person is not a bot');
+
+assert.equal(noIssueReason('Summary\n\nNo-Issue: typo fix\r\n'), 'typo fix', 'reason on its own line');
+assert.equal(noIssueReason('no-issue:   bump CI cache  '), 'bump CI cache', 'case and spaces');
+assert.equal(noIssueReason('No-Issue:'), null, 'empty reason');
+assert.equal(noIssueReason('No-Issue:   \nnext line'), null, 'blank reason does not span lines');
+assert.equal(noIssueReason('See No-Issue: below'), null, 'must start a line');
+assert.equal(noIssueReason('<!-- No-Issue: reason -->'), null, 'template comment');
+assert.equal(noIssueReason('<!--\nNo-Issue: reason\n-->'), null, 'multiline template comment');
+assert.equal(noIssueReason('<!--\nNo-Issue: reason'), null, 'unclosed template comment');
+assert.equal(noIssueReason('<!-- hint -->\nNo-Issue: real reason'), 'real reason', 'reason after a comment');
+assert.equal(noIssueReason(null), null, 'null body');
 console.log('ok');
diff --git a/.github/workflows/linked-issue.yml b/.github/workflows/linked-issue.yml
index afc7968..7a5b9fb 100644
--- a/.github/workflows/linked-issue.yml
+++ b/.github/workflows/linked-issue.yml
@@ -28,8 +28,12 @@ jobs:
               ...context.repo,
               pull_number: context.payload.pull_request.number,
             });
-            const { hasLinearKey, isBot } = require(`${process.env.GITHUB_WORKSPACE}/central/.github/scripts/linked-issue.js`);
+            const { hasLinearKey, isBot, noIssueReason } = require(`${process.env.GITHUB_WORKSPACE}/central/.github/scripts/linked-issue.js`);
             if (isBot(pr.user)) return;
-            if (!hasLinearKey(pr.title, pr.body, pr.head.ref)) {
-              core.setFailed('Add a Linear issue key to the PR title, body, or branch name.');
+            if (hasLinearKey(pr.title, pr.body, pr.head.ref)) return;
+            const reason = noIssueReason(pr.body);
+            if (reason) {
+              core.notice(`No linked issue: ${reason}`);
+              return;
             }
+            core.setFailed('Add a Linear issue key to the PR title, body, or branch name. Or add a "No-Issue: <reason>" line to the body.');
diff --git a/README.md b/README.md
index 0e6d21f..4bb1285 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,9 @@ The `linked-issue` check fails when a pull request has no Linear issue key, for
 
 Pull requests from GitHub App bots, such as Dependabot, pass.
 
-If the check fails, add the key to the title or the body. Then push a commit or run the check again. GitHub does not run the check again when you only edit the title or the body.
+If a pull request has no issue, add a line to the body that starts with `No-Issue:` and gives the reason, for example `No-Issue: fix a typo in the README`. The check passes and shows the reason as a notice. A `No-Issue:` line with no reason does not count.
+
+If the check fails, add the key to the title or the body, or add a `No-Issue:` line to the body. Then push a commit or run the check again. GitHub does not run the check again when you only edit the title or the body.
 
 ## Test