@@ -97,7 +97,9 @@ sign-off.
 
 The detection covers co-author and sign-off lines that name Claude Code, GitHub
 Copilot, Codex, Gemini, Cursor, Devin, Aider, Windsurf, Tabby or a model, and
-vendor marks such as "Generated with Claude Code". It matches the tools'
+vendor marks such as "Generated with Claude Code";
+[v2.19.0](../../changelog.md#v2190) added Amp, OpenHands, Factory Droid and
+Jules. It matches the tools'
 noreply addresses, so a human co-author who happens to be called Claude is left
 alone. [CC013](../../rules.md#cc013) keeps the current list.
 
 
@@ -11,6 +11,7 @@ below and to the page that documents the feature properly.
 
 | Version | What changed | Documented in |
 |---|---|---|
+| [2.19.0](#v2190) | Branch descriptions held to the Conventional Branch grammar; Amp, OpenHands, Factory Droid and Jules recognised | [CC201](rules.md#cc201) · [CC013](rules.md#cc013) |
 | [2.18.3](#v2183) | `--fix` corrects a message in place; `--branch` reads GitLab, Bitbucket, Azure and Jenkins variables | [Fixing a message in place](example.md#fixing-a-message-in-place) · [Other CI](guides/other-ci.md) |
 | [2.18.0](#v2180) | AI disclosure policy: three rules, and the correction written for you | [Policy guides](guides/policies.md#asking-for-disclosure-instead) · [CC014](rules.md#cc014) |
 | [2.17.0](#v2170) | Concrete corrections for mechanical slips; a `warn` level per rule | [Reading the JSON](example.md#reading-the-json) · [Report without enforcing](configuration.md#report-a-rule-without-enforcing-it) |
@@ -30,6 +31,53 @@ below and to the page that documents the feature properly.
 | [2.5.0](#v250) | Organization-wide config with `inherit_from` | [Across an organization](guides/organization.md) |
 | [2.0.0](#v200) | Configuration moved from YAML to TOML — breaking | [Migrating from v1](migration.md) |
 
+## v2.19.0 (2026-10-14) { #v2190 }
+
+### Added
+
+* **`require_description_grammar` checks what follows the branch type** —
+  `conventional_branch` checks the `<type>/` prefix and accepted anything
+  after it, so `feature/Add_Login`, `fix/header_bug` and `release/v1.-2.0`
+  all passed. With `[branch] require_description_grammar = true` the
+  description must follow the specification's grammar: lowercase letters and
+  digits, words joined by single hyphens, dots only inside a word. It is off
+  by default, because bot branches such as
+  `dependabot/npm_and_yarn/lodash-4.17.21` do not follow that grammar.
+  See PR [#581](https://github.com/commit-check/commit-check/pull/581) and
+  [CC201](rules.md#cc201).
+
+* **Amp, OpenHands, Factory Droid and Jules are recognised** — co-author and
+  sign-off lines naming them (`Amp <amp@ampcode.com>`, `openhands`,
+  `factory-droid[bot]`, `google-labs-jules[bot]`) and Amp's
+  `Amp-Thread-ID:` trailer now count as AI attribution, for
+  [CC013](rules.md#cc013) and for the `disclose` rules alike. People named
+  Jules or Amp are not flagged.
+  See PR [#606](https://github.com/commit-check/commit-check/pull/606) and
+  [Forbidding AI-attributed commits](guides/policies.md#forbidding-ai-attributed-commits).
+
+* **`--format json` says why a check was skipped** — a check skipped because
+  the author or a co-author is on an `ignore_authors` list carries a `reason`,
+  such as `author dependabot[bot] is in [commit].ignore_authors`. Every check
+  has the key; it is empty when there is no reason to give.
+  See PR [#605](https://github.com/commit-check/commit-check/pull/605) and
+  [When a check is skipped](example.md#when-a-check-is-skipped).
+
+### Fixed
+
+* **`check-tag` checks the tags a push sends** — under pre-commit the hook
+  judged the tags on `HEAD`, so a bad tag sent by `git push --follow-tags`
+  from another branch got through, and a tag push could be rejected over a
+  local tag on `HEAD` that it did not carry. It now checks the tag a tag push
+  names, and on a branch push the tags on every commit the push carries.
+  See PR [#603](https://github.com/commit-check/commit-check/pull/603).
+
+* **A GitHub Actions tag build has no branch to judge** — on a tag push,
+  `GITHUB_REF_NAME` holds the tag, so `--branch` failed
+  [CC201](rules.md#cc201) on `v1.2.0`. A tag build now falls back to `HEAD`,
+  which is always accepted, as tag builds on GitLab, Bitbucket, Azure and
+  Jenkins already did.
+  See PR [#603](https://github.com/commit-check/commit-check/pull/603).
+
 ## v2.18.3 (2026-10-07) { #v2183 }
 
 ### Added
 
@@ -222,10 +222,13 @@ allow_force_push = true            # set false to block force pushes
 [branch]
 # https://conventionalbranch.org
 conventional_branch = true
-# changed: spec types only. The default is a superset — these plus the
-# Conventional Commit types, AI agent prefixes and bot prefixes — so setting
-# this at all narrows it. Omit the line to accept all of them.
+# changed: the spec's five purpose types only. The default is a superset —
+# these plus their aliases feat and fix, AI agent prefixes, the other
+# Conventional Commit types and bot prefixes — so setting this at all narrows
+# it. Omit the line to accept all of them.
 allow_branch_types = ["feature", "bugfix", "hotfix", "release", "chore"]
+# true also holds the part after "/" to the spec's grammar
+require_description_grammar = false
 # allow_branch_names = []          # optional: extra standalone names, e.g. ["develop"]
 # require_rebase_target = "main"   # optional: no rebase requirement by default
 # ignore_authors = []              # optional: as above, for branch checks
@@ -261,7 +264,7 @@ Used from a hook definition, with no config file anywhere in the repository:
 ```yaml title=".pre-commit-config.yaml"
 repos:
   - repo: https://github.com/commit-check/commit-check
-    rev: v2.18.3
+    rev: v2.19.0
     hooks:
       - id: check-message
         args:
@@ -306,6 +309,7 @@ The full mapping between the three forms:
 | `conventional_branch = true` | `CCHK_CONVENTIONAL_BRANCH=true` | `--conventional-branch=true` |
 | `allow_branch_types = ["feature"]` | `CCHK_ALLOW_BRANCH_TYPES=feature,bugfix` | `--allow-branch-types=feature,bugfix` |
 | `allow_branch_names = ["develop"]` | `CCHK_ALLOW_BRANCH_NAMES=develop,staging` | `--allow-branch-names=develop,staging` |
+| `require_description_grammar = true` | `CCHK_REQUIRE_DESCRIPTION_GRAMMAR=true` | `--require-description-grammar=true` |
 | `require_rebase_target = "main"` | `CCHK_REQUIRE_REBASE_TARGET=main` | `--require-rebase-target=main` |
 | `allow_force_push = true` | `CCHK_ALLOW_FORCE_PUSH=true` | `--no-force-push` (sets `allow_force_push` to `false`) |
 | `ai_attribution = "forbid"` | `CCHK_AI_ATTRIBUTION=forbid` | `--ai-attribution=forbid` |
@@ -371,7 +375,8 @@ the same thing twice, so read the description rather than the cell:
 | commit | ai_disclosure_trailers | list[str] | ["Assisted-by", "Generated-by"] | The trailers that disclose AI assistance under `"disclose"`. The first one is what a correction is written with. Listing `Co-authored-by` says the project accepts the tool as a co-author, and CC015 then passes. `Signed-off-by` is refused: only a person can certify the DCO. |
 | commit | ai_disclosure_pattern | str | "" (any value) | A regex the disclosure trailer's value must match under `"disclose"`, e.g. `'^\S+/\S+$'` for an `agent/model` format. Empty accepts any value, but a trailer with no value at all is reported whatever the pattern is. |
 | branch | conventional_branch | bool | true | Enforce Conventional Branch specification. |
-| branch | allow_branch_types | list[str] | ["feature", "bugfix", "hotfix", "release", "chore", "feat", "fix", "build", "ci", "docs", "perf", "refactor", "style", "test", "ai", "claude", "codex", "copilot", "cursor", "dependabot", "renovate"] | Allowed branch types when `conventional_branch` is true. The default is a superset of the [Conventional Branch spec](https://conventionalbranch.org/): the spec types (`feature`, `bugfix`, `hotfix`, `release`, `chore`) plus the Conventional Commit types (`build`, `ci`, `docs`, `perf`, `refactor`, `style`, `test`), AI agent prefixes (`ai`, `claude`, `codex`, `copilot`, `cursor`) and bot prefixes (`dependabot`, `renovate`). For strict spec-only validation, set this option explicitly (e.g. `["feature", "bugfix", "hotfix", "release", "chore"]`). |
+| branch | allow_branch_types | list[str] | ["feature", "bugfix", "hotfix", "release", "chore", "feat", "fix", "build", "ci", "docs", "perf", "refactor", "style", "test", "ai", "claude", "codex", "copilot", "cursor", "dependabot", "renovate"] | Allowed branch types when `conventional_branch` is true. The default is a superset of the [Conventional Branch spec](https://conventionalbranch.org/): the spec's types (`feature`, `bugfix`, `hotfix`, `release`, `chore`, their aliases `feat` and `fix`, and the AI agent prefixes `ai`, `claude`, `codex`, `copilot`, `cursor`) plus the other Conventional Commit types (`build`, `ci`, `docs`, `perf`, `refactor`, `style`, `test`) and bot prefixes (`dependabot`, `renovate`). For strict spec-only validation, set this option explicitly to the spec's types; [CC201](rules.md#cc201) has the full config. |
+| branch | require_description_grammar | bool | false | Also hold the description after `<type>/` to the Conventional Branch grammar: lowercase letters and digits, words joined by single hyphens, dots only inside a word. Off by default, because bot branches such as `dependabot/npm_and_yarn/lodash-4.17.21` do not follow it. See [CC201](rules.md#cc201). |
 | branch | allow_branch_names | list[str] | [] (empty list) | Additional standalone branch names allowed when conventional_branch is true (e.g., ["develop", "staging"]). By default, master, main, HEAD, and PR-* are always allowed. |
 | branch | require_rebase_target | str | "" (no requirement) | Target branch for rebase requirement. If not set, no rebase validation is performed. |
 | push | allow_force_push | bool | true | Allow force pushes. Set to `false` to block force pushes when used as a pre-push hook or with `--no-force-push`. |
 
@@ -159,7 +159,7 @@ pushed:
 ```yaml title=".pre-commit-config.yaml"
 repos:
   - repo: https://github.com/commit-check/commit-check
-    rev: v2.18.3
+    rev: v2.19.0
     hooks:
       - id: check-no-force-push
         stages: [pre-push]
@@ -286,6 +286,18 @@ $ echo "Merge branch 'main' into topic" | commit-check -m --no-banner
 ```
 
 In JSON each skipped check carries `"status": "skip"`, distinct from `"pass"`.
+When a check is skipped because the author or a co-author is on an
+`ignore_authors` list, `reason` says so. Here `HEAD` is a Dependabot commit
+and `cchk.toml` lists `dependabot[bot]` under `[commit] ignore_authors`:
+
+```console
+$ commit-check -m --rev HEAD --format json | jq -c '.checks[] | {rule_id, status, reason}'
+{"rule_id":"CC001","status":"skip","reason":"author dependabot[bot] is in [commit].ignore_authors"}
+{"rule_id":"CC004","status":"skip","reason":"author dependabot[bot] is in [commit].ignore_authors"}
+{"rule_id":"CC005","status":"skip","reason":"author dependabot[bot] is in [commit].ignore_authors"}
+```
+
+For any other skip, such as a merge subject, `reason` is empty.
 
 !!! warning "A green run can still have validated nothing"
 
@@ -323,7 +335,8 @@ $ echo "Fix: add streaming support" | commit-check -m --format json | jq '.check
   "error": "The commit message should follow Conventional Commits. See https://www.conventionalcommits.org",
   "suggest": "Use \"fix: add streaming support\"",
   "fix": "fix: add streaming support",
-  "docs_url": "https://commit-check.com/rules/#cc001"
+  "docs_url": "https://commit-check.com/rules/#cc001",
+  "reason": ""
 }
 ```
 
 
@@ -132,13 +132,18 @@ Docs: https://commit-check.com/rules/#cc013
 ```
 
 Recognised signatures are co-author and sign-off lines naming Claude Code,
-GitHub Copilot, Codex, Gemini, Cursor, Devin, Aider, Windsurf and Tabby, the
-disclosure trailers `Assisted-by:` and `Generated-by:`, vendor marks such as
-`🤖 Generated with Claude Code`, and generic AI model names. This is the
+GitHub Copilot, Codex, Gemini, Cursor, Devin, Aider, Windsurf, Tabby, Amp,
+OpenHands, Factory Droid and Jules, the disclosure trailers `Assisted-by:` and
+`Generated-by:`, vendor marks such as `🤖 Generated with Claude Code` and
+Amp's `Amp-Thread-ID:`, and generic AI model names. This is the
 position [Kubernetes](https://www.kubernetes.dev/docs/guide/pull-requests/)
 takes — no AI trailers in the history, disclosure in the pull request
 instead.
 
+These rules read only the message. Jules and OpenHands can commit under their
+own bot identity instead of adding a co-author line, and such a commit passes
+when its message carries no trailer.
+
 !!! warning "This checks disclosure, not authorship"
 
     These rules read commit metadata. They detect a commit that *says* it
 
@@ -8,7 +8,7 @@ Add Commit Check to `.pre-commit-config.yaml`:
 ```yaml title=".pre-commit-config.yaml"
 repos:
   - repo: https://github.com/commit-check/commit-check
-    rev: v2.18.3
+    rev: v2.19.0
     hooks:
       - id: check-message
       - id: check-branch
@@ -50,6 +50,10 @@ The three `pre-push` hooks need their own install too:
 $ pre-commit install --hook-type pre-push
 ```
 
+`check-tag` checks the tags the push sends: the tag a tag push names, and on
+a branch push, such as `git push --follow-tags`, the tags on every commit the
+push carries.
+
 pre-commit runs no hook for a push that creates a ref without carrying new
 commits. So a new tag pushed on its own, when the commit it points at is
 already on the remote, is never seen by `check-tag`.
@@ -61,7 +65,7 @@ Options can be passed as hook arguments, which keeps everything in one file:
 ```yaml title=".pre-commit-config.yaml"
 repos:
   - repo: https://github.com/commit-check/commit-check
-    rev: v2.18.3
+    rev: v2.19.0
     hooks:
       - id: check-message
         args:
@@ -83,7 +87,7 @@ colon, and lets the commit through:
 ```yaml title=".pre-commit-config.yaml"
 repos:
   - repo: https://github.com/commit-check/commit-check
-    rev: v2.18.3
+    rev: v2.19.0
     hooks:
       - id: check-message
         args: [--fix]
 
@@ -70,6 +70,7 @@ Every function returns the same shape:
             "suggest": "...",    # advice for a person
             "fix": "...",        # the corrected value, or "" when it takes judgment
             "docs_url": "https://commit-check.com/rules/#cc001",
+            "reason": "...",     # why a skipped check did not run, when known; else ""
         },
     ],
 }
@@ -80,7 +81,8 @@ Every function returns the same shape:
 - **`skip` is not `pass`.** A check skips when it never ran — the author is in
   `ignore_authors`, or there was nothing to check — and the top-level `status`
   is `skip` only when every check skipped. A skipped run validated nothing, so
-  do not read it as approval.
+  do not read it as approval. When the author or a co-author is in
+  `ignore_authors`, the check's `reason` names them.
 - **`warn`** is a rule listed under the config's `warn`: reported in full,
   never a failure. The top-level `status` stays `pass`, and `warnings` counts
   them.
 
@@ -537,9 +537,10 @@ git commit --amend --signoff
 
 Rejects a commit whose message carries any AI attribution: a co-author or
 sign-off line naming Claude Code, Copilot, Codex, Gemini, Cursor, Devin,
-Aider, Windsurf or Tabby, a disclosure trailer such as `Assisted-by:` or
-`Generated-by:`, a vendor's own mark such as `🤖 Generated with Claude Code`,
-and generic AI model names.
+Aider, Windsurf, Tabby, Amp, OpenHands, Factory Droid or Jules, a disclosure
+trailer such as `Assisted-by:` or `Generated-by:`, a vendor's own mark such
+as `🤖 Generated with Claude Code` or Amp's `Amp-Thread-ID:` trailer, and
+generic AI model names.
 
 **Why is this bad?**
 
@@ -762,6 +763,11 @@ Checks that the current branch name follows the
 
 `master`, `main`, `HEAD`, and `PR-*` are always accepted.
 
+By default only the type is checked, and any description after the `/` is
+accepted. With `require_description_grammar` the description has to follow
+the specification's grammar too: lowercase letters and digits, words joined
+by single hyphens, dots only inside a word, as in `release/v1.2.0`.
+
 **Why is this bad?**
 
 A predictable prefix is something automation can act on: CI can skip expensive
@@ -787,14 +793,35 @@ feature/role-caching
 
 * `branch.conventional_branch` — set to `false` to disable this rule.
 * `branch.allow_branch_types` — the accepted `<type>` values. The default is
-  a superset of the specification: the spec types plus the Conventional Commit
-  types, AI agent prefixes (`ai`, `claude`, `codex`, `copilot`,
-  `cursor`), and bot prefixes (`dependabot`, `renovate`). Set it
-  explicitly for strict spec-only validation.
+  a superset of the specification: the spec's types (`feature`, `bugfix`,
+  `hotfix`, `release`, `chore`, their aliases `feat` and `fix`, and the AI
+  agent prefixes `ai`, `claude`, `codex`, `copilot` and `cursor`), plus the
+  other Conventional Commit types and the bot prefixes `dependabot` and
+  `renovate`. Set it explicitly for strict spec-only validation.
+* `branch.require_description_grammar` — set to `true` to hold the
+  description to the specification's grammar, so `feature/Add_Login`,
+  `feature/new--login` and `feature/a/b` are rejected. Off by default,
+  because bot branches such as `dependabot/npm_and_yarn/lodash-4.17.21` do
+  not follow it.
 * `branch.allow_branch_names` — additional standalone names to accept, such as
   `["develop", "staging"]`.
 * `branch.ignore_authors` — bypass the check for specific authors.
 
+To check branches exactly as the specification does, set the spec's types,
+the description grammar, and its third trunk branch, `develop`:
+
+```toml title="cchk.toml"
+[branch]
+conventional_branch = true
+allow_branch_types = ["feature", "feat", "bugfix", "fix", "hotfix", "release", "chore", "ai", "claude", "codex", "copilot", "cursor"]
+require_description_grammar = true
+allow_branch_names = ["develop"]
+```
+
+With that, `commit-check --branch` agrees with every case of the
+specification's [conformance suite](https://github.com/conventional-branch/conventional-branch/blob/main/tests/fixtures.json)
+that git can create as a branch.
+
 ### merge-base (CC202) { #cc202 }
 
 **What it does**