diff --git a/lib/review-brief.ts b/lib/review-brief.ts
index 67086d89e..093f37c4b 100644
--- a/lib/review-brief.ts
+++ b/lib/review-brief.ts
@@ -142,7 +142,7 @@ function renderRole(role: BriefRole, slots: Slots, t: SectionTexts): string {
  */
 export function workspaceParagraph(dir: string): string {
   const q = `'${dir.replace(/'/g, `'\\''`)}'`;
-  return `Workspace: the checkout under review is ${dir}. Your shell and file tools may start in another checkout, and every command runs in a fresh shell: begin each command with \`cd ${q} && \`, and give every file read, search, edit or write an absolute path under ${dir}. Make the first line of your final reply the line \`cd ${q} && echo "REVIEWED_TREE: $(git rev-parse 'HEAD^{tree}') $(git rev-parse --show-toplevel)"\` prints, even where this brief limits your output to findings; a reply without it, or from another checkout, does not count.`;
+  return `Workspace: the checkout under review is ${dir}. Your shell and file tools may start in another checkout, and every command runs in a fresh shell: begin each command with \`cd ${q} && \`, and give every file read, search, edit or write an absolute path under ${dir}. Start your final reply with the bare line \`REVIEWED_TREE: <tree> <toplevel>\`, even where this brief limits your output to findings: nothing before it, not the command and not a label. Get the line by running \`cd ${q} && echo "REVIEWED_TREE: $(git rev-parse 'HEAD^{tree}') $(git rev-parse --show-toplevel)"\` and copy what it prints. A reply without that line, or from another checkout, does not count.`;
 }
 export const withWorkspace = (text: string, dir: string) => `${text}\n\n${workspaceParagraph(dir)}`;
 /** The checkout a brief names: the toplevel of the directory the bins run in, where its diff and merge base come from. */
@@ -152,11 +152,11 @@ export function checkoutRoot(): string {
 }
 
 /**
- * One REVIEWED_TREE line as "<tree> <toplevel>", or null. A list marker or heading mark may lead it, and a whole-line `**…**` or
+ * One REVIEWED_TREE line as "<tree> <toplevel>", or null. A list marker, heading mark or `printed:` label (GST-776) may lead it, and a whole-line `**…**` or
  * backtick wrapper, a bold label and backticks around the sha or the whole path are removed; the path's own characters are kept.
  */
 function parseTreeLine(line: string): string | null {
-  let t = line.trim().replace(/^(?:[-*>]\s+|\d+[.)]\s+|#+\s+)/, '');
+  let t = line.trim().replace(/^(?:[-*>]\s+|\d+[.)]\s+|#+\s+)/, '').replace(/^[Pp]rinted:\s+/, '');
   for (const w of ['**', '`']) if (t.length > 2 * w.length && t.startsWith(w) && t.endsWith(w)) t = t.slice(w.length, -w.length).trim();
   const m = /^(?:\*\*REVIEWED_TREE:\*\*|REVIEWED_TREE:)\s+`?([0-9a-f]{40,64})`?\s+(.+)$/.exec(t);
   if (!m) return null;
diff --git a/test/review-dispatch.test.ts b/test/review-dispatch.test.ts
index 7a5cf7c41..72d0d2580 100644
--- a/test/review-dispatch.test.ts
+++ b/test/review-dispatch.test.ts
@@ -580,3 +580,41 @@ describe('reading the REVIEWED_TREE line (GST-482 review fixes)', () => {
     expect(r.stderr).toContain('BRIEF_RENDER_FAILED: cannot read HEAD^{tree} and the toplevel of');
   });
 });
+
+describe('the REVIEWED_TREE line as GBRA-218 readers wrote it (GST-776)', () => {
+  const top = fs.realpathSync(spawnSync('git', ['rev-parse', '--show-toplevel'], { cwd: ROOT, encoding: 'utf8', timeout: 30_000 }).stdout.trim());
+  const tree = spawnSync('git', ['rev-parse', 'HEAD^{tree}'], { cwd: ROOT, encoding: 'utf8', timeout: 30_000 }).stdout.trim();
+  const command = `cd '${top}' && echo "REVIEWED_TREE: $(git rev-parse 'HEAD^{tree}') $(git rev-parse --show-toplevel)"`;
+  // Value: protects=a reader that reviewed the right checkout is not failed for how it wrote its fingerprint; fails_when=the brief asks for "the line <command> prints" (two Sonnet 5.5 low readers then wrote `printed: REVIEWED_TREE: …` and were failed as reported="none"), or a `printed:` prefix lets a wrong tree through;
+  //   why_new=GBRA-218 pass restarts on gstack 1.92.25.0; seam=lib/review-brief.ts workspaceParagraph and checkReviewedTree via gstack-review-dispatch collect; no_claim=that every model now writes the bare line
+  test('the brief asks for the bare line first and gives the command only as the way to get it', () => {
+    const p = workspaceParagraph(top);
+    expect(p).not.toContain('the line `cd');
+    const bare = p.indexOf('`REVIEWED_TREE: <tree> <toplevel>`');
+    expect(bare).toBeGreaterThan(0);
+    expect(p.indexOf(command)).toBeGreaterThan(bare);
+  });
+
+  test('the echoed command then a printed: line is read; the same shape with a wrong tree or checkout is still refused', () => {
+    const reply = (fingerprint: string) => `${command}\nprinted: REVIEWED_TREE: ${fingerprint}\nNO FINDINGS\n`;
+    expect(checkReviewedTree(reply(`${tree} ${top}`), `${tree} ${top}`)).toMatchObject({ ok: true });
+    expect(checkReviewedTree(reply(`${'b'.repeat(40)} ${top}`), `${tree} ${top}`)).toMatchObject({ ok: false, moved: true, reported: `${'b'.repeat(40)} ${top}` });
+    expect(checkReviewedTree(reply(`${tree} /elsewhere`), `${tree} ${top}`)).toMatchObject({ ok: false, moved: false, reported: `${tree} /elsewhere` });
+    expect(checkReviewedTree(`Note: REVIEWED_TREE: ${tree} ${top}\nNO FINDINGS`, `${tree} ${top}`).reported).toBe('none');
+
+    const out = tmp();
+    const ledger = path.join(out, 'review-ledger.jsonl');
+    const merged = path.join(out, 'merged.jsonl');
+    const file = field(run(['render', '--role', 'specialist', '--name', 'testing', '--out', out, '--diff-base', SHA]).stdout, 'file');
+    run(['sent', '--ledger', ledger, '--role', 'specialist', '--name', 'testing', '--sent', file]);
+    const collectReply = (text: string) => {
+      const f = path.join(out, 'reply.out');
+      fs.writeFileSync(f, text);
+      return spawnSync(BIN, ['collect', '--ledger', ledger, '--role', 'specialist', '--name', 'testing', '--output', f, '--merged', merged], { cwd: ROOT, encoding: 'utf8', timeout: 60_000 });
+    };
+    const wrong = collectReply(reply(`${'b'.repeat(40)} ${top}`));
+    expect([wrong.status, wrong.stdout.startsWith('COLLECT_TREE_MOVED: reader=specialist/testing')]).toEqual([1, true]);
+    const right = collectReply(reply(`${tree} ${top}`));
+    expect(right.stdout).toStartWith('COLLECT: reader=specialist/testing findings=0 ');
+  });
+});