diff --git a/.github/scripts/enqueue-guard.test.mjs b/.github/scripts/enqueue-guard.test.mjs
index 2e85ad4e4..cf5615b91 100644
--- a/.github/scripts/enqueue-guard.test.mjs
+++ b/.github/scripts/enqueue-guard.test.mjs
@@ -425,8 +425,10 @@ test('#943, reworded by #947: a Reviewer: outside both vocabularies is refused a
   assert.ok(r.reasons.includes('Reviewer names "someone-else", who is not a writers Bot name'), r.reasons.join('; '))
 })
 
+// `Birfy` used to stand here as the second spelling; since #1228 it is the one value neither line may name,
+// so the @ and the case are shown on the listed login itself.
 test('#943: an @ and any case are fine on a login `reviewers` lists', () => {
-  const r = run({ body: 'Owner: Dev\nReviewer: @Reviewer-Agent, BIRFY\nFixes #943\n', comments: [comment()] })
+  const r = run({ body: 'Owner: Dev\nReviewer: @Reviewer-Agent, REVIEWER-AGENT\nFixes #943\n', comments: [comment()] })
   assert.equal(r.ok, true, r.reasons.join('; '))
 })
 
@@ -440,7 +442,9 @@ test('#947: a Reviewer: naming a writers Bot name is accepted', () => {
 })
 
 test('#947: either vocabulary is accepted, with an @ and in any case', () => {
-  for (const line of ['Reviewer: @Reviewer2', 'Reviewer: reviewer', 'Reviewer: Birfy', 'Reviewer: Reviewer2, Birfy', 'Reviewer: reviewer-agent, @REVIEWER2']) {
+  // `Reviewer: Birfy` and `Reviewer: Reviewer2, Birfy` sat in this list until #1228 made the shared identity
+  // a refusal of its own; the cases that keep them out are the `#1228:` ones below.
+  for (const line of ['Reviewer: @Reviewer2', 'Reviewer: reviewer', 'Reviewer: reviewer-agent, @REVIEWER2']) {
     const r = run({ body: `Owner: Dev\n${line}\nFixes #947\n`, comments: [comment()] })
     assert.equal(r.ok, true, `${line}: ${r.reasons.join('; ')}`)
   }
@@ -571,8 +575,10 @@ test('#951: overlap in either direction, in a list, or through @ and case is ref
   assert.equal(ok.ok, true, ok.reasons.join('; '))
 })
 
-// `Birfy` is both a `reviewers` login and the one identity every Bot writes as, so it is the sharpest
-// fixture: each line alone is perfectly valid, and only the comparison can refuse it.
+// `Birfy` is both a `reviewers` login and the one identity every Bot writes as. Until #1228 that made it the
+// sharpest fixture for this comparison — each line alone looked valid and only the comparison could refuse
+// it; the value is now refused on its own too (:the `#1228:` cases below), so this one pins that the overlap
+// refusal is still there beside it, unchanged.
 test('#951: a name that is both a login and a writers name is refused on both lines', () => {
   const r = run({ body: 'Owner: Birfy\nReviewer: Birfy\nFixes #951\n', comments: [comment()] })
   assert.equal(r.ok, false)
@@ -664,6 +670,63 @@ test('#962: Docs is registered in writers; Owner: Docs passes and an unknown own
 })
 
 
+// #1228: the two lines name a workstation, but `reviewers` (logins) and `writers` (Bot names) overlap on
+// exactly one value — `Birfy`, the shared identity every Bot writes as. Each line alone looked valid, so a
+// body could name no Bot at all and still enter the queue; #1214 merged with `Reviewer: Birfy`. The value is
+// refused on either line, with the same normalisation (`@`, case) the two vocabularies already use.
+const SHARED_OWNER = 'Owner names "birfy", who is the shared write identity every Bot writes as — name the Bot that claims this pull request'
+const SHARED_REVIEWER = 'Reviewer names "birfy", who is the shared write identity every Bot writes as — name the Bot that reviews'
+const sharedRefusals = (r) => r.reasons.filter((reason) => /is the shared write identity/.test(reason))
+
+test('#1228: Reviewer: Birfy names no reviewer, and the refusal names the line and the value', () => {
+  const r = run({ body: 'Owner: Dev3\nReviewer: Birfy\nFixes #1228\n', comments: [comment()] })
+  assert.equal(r.ok, false)
+  assert.deepEqual(sharedRefusals(r), [SHARED_REVIEWER])
+})
+
+test('#1228: Owner: Birfy claims no owner, and the refusal names the line and the value', () => {
+  const r = run({ body: 'Owner: Birfy\nReviewer: Reviewer\nFixes #1228\n', comments: [comment()] })
+  assert.equal(r.ok, false)
+  assert.deepEqual(sharedRefusals(r), [SHARED_OWNER])
+})
+
+test('#1228: two real Bots on the two lines are still accepted', () => {
+  for (const body of ['Owner: Dev3\nReviewer: Reviewer\nFixes #1228\n', 'Owner: Dev3\nReviewer: reviewer-agent\nFixes #1228\n']) {
+    const r = run({ body, comments: [comment()] })
+    assert.equal(r.ok, true, `${body}: ${r.reasons.join('; ')}`)
+    assert.deepEqual(sharedRefusals(r), [], `${body}: the rule is about one value, not about the lines`)
+  }
+})
+
+test('#1228: @ and case are normalised first, so the shared identity is refused once, not twice', () => {
+  const r = run({ body: 'Owner: Dev3\nReviewer: @BIRFY\nFixes #1228\n', comments: [comment()] })
+  assert.equal(r.ok, false)
+  assert.deepEqual(sharedRefusals(r), [SHARED_REVIEWER])
+})
+
+test('#1228: one unusable name in a list is enough', () => {
+  const r = run({ body: 'Owner: Dev3\nReviewer: Birfy, Reviewer\nFixes #1228\n', comments: [comment()] })
+  assert.equal(r.ok, false)
+  assert.deepEqual(sharedRefusals(r), [SHARED_REVIEWER])
+})
+
+test('#1228: the shared identity on both lines is refused on both, and the overlap refusal is unchanged', () => {
+  const r = run({ body: 'Owner: Birfy\nReviewer: Birfy\nFixes #1228\n', comments: [comment()] })
+  assert.equal(r.ok, false)
+  assert.deepEqual(sharedRefusals(r), [SHARED_OWNER, SHARED_REVIEWER])
+  assert.deepEqual(selfReviewRefusals(r), ['Reviewer names "birfy", who is also the Owner of this pull request'])
+})
+
+// The checkpoint compares `claim` with the Owner names, so it cannot become the way in: an Owner line that
+// names nobody is already refused, and nothing new is added to the block.
+test('#1228: the checkpoint cannot become the way in — claim "Birfy" under Owner: Birfy is refused', () => {
+  const body = `Owner: Birfy\nReviewer: Reviewer\nFixes #1228\n\n${checkpoint({ claim: 'Birfy', issue: 1228 })}`
+  const r = run({ raw: true, body, comments: [comment()] })
+  assert.equal(r.ok, false)
+  assert.deepEqual(sharedRefusals(r), [SHARED_OWNER])
+  assert.equal(r.reasons.some((reason) => /checkpoint field "claim"/.test(reason)), false, 'no new field rule: the Owner line is what refuses it')
+})
+
 // ---- #1112: the guard reported a PASS that had not been posted yet, and a re-push could go green again.
 // The three cases below are one per failure mode the issue names; each is red on the code before it.
 
diff --git a/.github/scripts/enqueue-rules.mjs b/.github/scripts/enqueue-rules.mjs
index 003e25912..237c2a360 100644
--- a/.github/scripts/enqueue-rules.mjs
+++ b/.github/scripts/enqueue-rules.mjs
@@ -56,6 +56,12 @@ const labelNames = (labels) => (labels ?? []).map((l) => String(typeof l === 'st
 // A Bot name can only through the one identity every Bot writes as, `Birfy`, so it names a reviewer only
 // while that account is in `reviewers`; with it gone the name is vocabulary and the line is refused.
 const SHARED_WRITE_LOGIN = 'Birfy'
+// #1228: that same account is the one value both vocabularies contain, so both lines accepted it: a body
+// could name `Birfy` on `Owner:` (a `writers` name) or on `Reviewer:` (a `reviewers` login) and the queue
+// entry read it as a workstation. #1214 merged with `Reviewer: Birfy` for exactly that reason. Neither line
+// is about the account; each asks which Bot claims, and which Bot reviews, so the shared identity is refused
+// before either vocabulary is consulted — otherwise "listed" would keep standing in for "named a Bot".
+const SHARED_WRITE_NAME = SHARED_WRITE_LOGIN.toLowerCase()
 // One line's names: split on commas, strip a leading `@`, compare case-insensitively. Both header lines
 // read their values this way so `@Dev`, `dev` and `DEV` are one name wherever they appear (#951).
 const headerNames = (line, pattern) => line.replace(pattern, '').split(',').map((value) => value.trim().replace(/^@/, '').toLowerCase()).filter(Boolean)
@@ -73,7 +79,8 @@ function headerReasons(body, policy) {
   const ownerNames = owner ? [...new Set(headerNames(owner, OWNER_LINE))] : []
   if (!ownerNames.length) reasons.push('missing line: Owner:')
   for (const name of ownerNames) {
-    if (!bots.has(name)) reasons.push(`Owner names "${name}", who is not a writers Bot name`)
+    if (name === SHARED_WRITE_NAME) reasons.push(`Owner names "${name}", who is the shared write identity every Bot writes as — name the Bot that claims this pull request`)
+    else if (!bots.has(name)) reasons.push(`Owner names "${name}", who is not a writers Bot name`)
   }
   const owners = new Set(ownerNames)
   const reviewer = lines.find((line) => REVIEWER_LINE.test(line))
@@ -84,6 +91,11 @@ function headerReasons(body, policy) {
     if (!names.length) reasons.push('missing line: Reviewer:')
     let passable = false
     for (const name of names) {
+      // #1228: refused before the vocabularies, because this value is the one both of them list.
+      if (name === SHARED_WRITE_NAME) {
+        reasons.push(`Reviewer names "${name}", who is the shared write identity every Bot writes as — name the Bot that reviews`)
+        continue
+      }
       if (logins.has(name)) {
         passable = true
         continue
diff --git a/.github/scripts/merge-gate.test.mjs b/.github/scripts/merge-gate.test.mjs
index c7ddcacfd..a4e46fe86 100644
--- a/.github/scripts/merge-gate.test.mjs
+++ b/.github/scripts/merge-gate.test.mjs
@@ -409,7 +409,7 @@ const queueReal = (fx, body = fx.comment.body, pullBody) => main({
     if (path.includes('/files')) return fx.files.map((filename) => JSON.stringify({ filename })).join('\n')
     if (path.includes('/comments')) return JSON.stringify({ user: { login: fx.comment.login }, body, created_at: fx.comment.created_at, author_association: 'OWNER' })
     if (path.includes('/reviews')) return ''
-    if (/\/pulls\/\d+$/.test(path)) return JSON.stringify({ head: { sha: fx.head, repo: { full_name: 'ThinkFlowLab/FlyBot' } }, user: { login: fx.author }, labels: [{ name: 'agent-pr' }], body: pullBody ?? bodyWithCheckpoint(['Owner: Reviewer', 'Reviewer: Birfy', 'Fixes #' + fx.pr, ''].join('\n'), fx.files, fx.pr) })
+    if (/\/pulls\/\d+$/.test(path)) return JSON.stringify({ head: { sha: fx.head, repo: { full_name: 'ThinkFlowLab/FlyBot' } }, user: { login: fx.author }, labels: [{ name: 'agent-pr' }], body: pullBody ?? bodyWithCheckpoint(['Owner: Reviewer', 'Reviewer: Reviewer2', 'Fixes #' + fx.pr, ''].join('\n'), fx.files, fx.pr) })
     throw new Error('fake gh: unexpected ' + path)
   },
   env: { GITHUB_STEP_SUMMARY: '', REVIEW_POLICY: REAL_POLICY, GH_REPO: 'ThinkFlowLab/FlyBot', HEAD_REF: `refs/heads/gh-readonly-queue/main/pr-${fx.pr}-c74e1207${'0'.repeat(32)}`, MODE: 'queue' },
@@ -454,7 +454,7 @@ test('#660-#663: a PASS from another GitHub login still passes; the author\'s ow
 test('#644: #663 passes once the author comment attests a role that is not the Owner', () => {
   const fx = REAL.find((f) => f.pr === 663)
   const body = fx.comment.body.replace('Written-by: Reviewer\n', `Written-by: Reviewer\nAttestation: ${fx.head} role=Reviewer\n`)
-  const result = queueReal(fx, body, bodyWithCheckpoint(`Owner: Dev\nReviewer: Birfy\nFixes #${fx.pr}\n`, fx.files, fx.pr))
+  const result = queueReal(fx, body, bodyWithCheckpoint(`Owner: Dev\nReviewer: Reviewer2\nFixes #${fx.pr}\n`, fx.files, fx.pr))
   assert.equal(result.ok, true, result.reasons.join('; '))
   assert.equal(result.verdict.by, 'Birfy')
 })
diff --git a/AGENTS.md b/AGENTS.md
index ba44d05f0..0f7ce11a3 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -175,7 +175,7 @@ What this buys is presence and a name from a closed list, not truth: with one sh
 - **An author-login comment is not a review (#644, option B, first slice).** When the conclusion's GitHub login is the pull request author, `selfReview` is not enough. The header — the lines before the first blank, and within the first eight non-empty lines — carries `Attestation: <40-character sha> role=<Bot>`. The sha is the whole tip (#1112). `role` is the `Written-by` name. That role is not an `Owner:` of the pull request. A free-form comment, a `Verdict:` with no attestation line, a line after the blank, a short sha, a role that is not the `Written-by` name, or a role that is the Owner refuses. A conclusion from a different GitHub login is unchanged. `decide` in [`review-gate.mjs`](.github/scripts/review-gate.mjs) is the check, and the reviewed-tip job, `enqueue-guard` and `merge-gate` all call it. The line is parsed, not signed. A signature was carved out later (#644) and is shipped but not enabled (#1110, #1111): the `signers` roster is empty, so no conclusion is signed today. T0/T1 still need no PASS.
 - **`hold` is human-only.** Only a person sets the label and only a person lifts it; automation refuses a held pull request and never removes the label itself. That is the one human input left on the merge path.
 - **The label awaiting-approval is retired.** A PASS at the tip goes straight to the queue through the enqueue guard (#687); no pull request waits for an approval click and the label is not set again.
-- **A pull request enters the queue with its issue and its `agent-pr` label.** On a branch this repository owns, the enqueue guard also refuses one whose body names no issue (`Fixes #<n>` / `Closes #<n>`) and one without the `agent-pr` label (#718), so "one issue, one pull request" is checked rather than remembered. It refuses a **live, non-draft** request whose body carries no `Owner:` line or no `Reviewer:` line in its first 20 lines, or a `Reviewer:` that is neither a `reviewers` login nor a `writers` Bot name, or that names nobody who can record a PASS — a Bot name counts only through the one identity every Bot writes as, `Birfy`, so it names nobody while that account is outside `reviewers` (#947); a `Reviewer:` that names the same Bot as the `Owner:` is refused too, compared name by name after commas, a leading `@` and case are normalised, because one Bot owning and reviewing the same pull request is the shape #940 had with no lines at all (#951); both lines also need a value the policy knows — a `Reviewer:` outside both vocabularies and an `Owner:` outside `writers` are refused, and a line with no value is the missing line, so an empty `Owner:` cannot clear the comparison (#951); the refusal names the missing line, or the word and the list it missed (#943, #947, #951; #940 merged in about seven minutes with the largest diff of the day and neither line). A **merged** pull request is never re-judged: this check also runs on every comment, and history is not a request. Two exemptions: a mechanical release PR, which carries neither by design, and a **fork** (`pull.head.repo.full_name` is not this repository), whose head we cannot push to and where the contributor keeps their own workflow.
+- **A pull request enters the queue with its issue and its `agent-pr` label.** On a branch this repository owns, the enqueue guard also refuses one whose body names no issue (`Fixes #<n>` / `Closes #<n>`) and one without the `agent-pr` label (#718), so "one issue, one pull request" is checked rather than remembered. It refuses a **live, non-draft** request whose body carries no `Owner:` line or no `Reviewer:` line in its first 20 lines, or a `Reviewer:` that is neither a `reviewers` login nor a `writers` Bot name, or that names nobody who can record a PASS — a Bot name counts only through the one identity every Bot writes as, `Birfy`, so it names nobody while that account is outside `reviewers` (#947); a `Reviewer:` that names the same Bot as the `Owner:` is refused too, compared name by name after commas, a leading `@` and case are normalised, because one Bot owning and reviewing the same pull request is the shape #940 had with no lines at all (#951); both lines also need a value the policy knows — a `Reviewer:` outside both vocabularies and an `Owner:` outside `writers` are refused, and a line with no value is the missing line, so an empty `Owner:` cannot clear the comparison (#951); neither line may name `Birfy`, the one identity every Bot writes as, because it is the single value both vocabularies list and so names no workstation at all (#1228); the refusal names the missing line, or the word and the list it missed (#943, #947, #951; #940 merged in about seven minutes with the largest diff of the day and neither line). A **merged** pull request is never re-judged: this check also runs on every comment, and history is not a request. Two exemptions: a mechanical release PR, which carries neither by design, and a **fork** (`pull.head.repo.full_name` is not this repository), whose head we cannot push to and where the contributor keeps their own workflow.
 
 **`enqueue-guard` writes a check on the head, and the queue's ruleset does not require it** (#812, re-read 2026-10-24). Team pull requests merge upstream in `ThinkFlowLab/FlyBot` through the `main merge queue`, whose ruleset requires three contexts — `Node 24 · DSH 0.2.0-rc.2`, `tests-ok` and `merge-gate`; the paragraph below (#960) is how `merge-gate` reads the body the queue does not read. `enqueue-guard` still runs on that head, and on the queue entry: [`enqueue-guard.yml`](.github/workflows/enqueue-guard.yml) takes its code from `main` and never from the pull request, on every event that can change the answer for a fixed head — a push, a label added or removed, a comment, a review body, or a manual run — and calls [`enqueue-guard.mjs`](.github/scripts/enqueue-guard.mjs)'s own decision, the same function that prints the command, so the check and the command cannot disagree. It refuses a head that carries a `hold`, a pull request with no `agent-pr`, or a body that names no issue, and — **for T2 and T3 only** — a head that has no PASS naming that exact tip or a PASS that lists no `Ran:`; a T0/T1 change and the mechanical release pull request need no PASS at all, because the tier is computed from the diff and never read from a `risk:T*` label (#640). A new commit is a new head and a new check run, and a green check never carries over.
 
diff --git a/docs/autonomous-dev.md b/docs/autonomous-dev.md
index a6d803d61..fda1434e6 100644
--- a/docs/autonomous-dev.md
+++ b/docs/autonomous-dev.md
@@ -294,7 +294,8 @@ PASS is never a queue permit on its own (#602); on a live, non-draft pull reques
 Bot name, or a Bot name whose shared `Birfy` identity is not in `reviewers`, #947, or a `Reviewer:` naming the same Bot as
 the `Owner:`, compared per name after commas, `@` and case, #951; both lines need a value the policy knows — an `Owner:`
 outside `writers` is refused and a line with no value is the missing line, so an empty `Owner:` cannot clear the
-comparison, #951), naming the missing line or the word
+comparison, #951; and neither line may name the shared `Birfy` identity, the one value both vocabularies list and so the
+one value that names no workstation, #1228), naming the missing line or the word
 that missed both lists (#943) — a merged pull request is not re-judged, because this check also runs on every comment; the
 same call refuses a body whose `## Checkpoint` block is missing or wrong, one field at a time ([AGENTS.md → The checkpoint
 block](../AGENTS.md#the-checkpoint-block-a-hand-off-the-next-bot-can-read-1202), skeleton in