@@ -0,0 +1,11 @@
+---
+'@objectstack/skills': patch
+---
+
+docs(skills): teach that a save and `os validate` refuse `titleFormat`
+
+Clause-②: no
+Metadata-protocol: none
+
+- `objectstack-data` (object properties table) and `objectstack-formula` (template carriers) no longer call `titleFormat` deprecated: since #29499 the metadata save gate and `os validate` refuse an object that declares it (`title-format-retired`), and it moves to `nameField`. The formula skill drops the sentence that restated the template grammar cell beside it.
+- ADR-0079 D3 gains a dated amendment note citing ruling 6574393684 and #29499; the decision is unchanged.
@@ -1,6 +1,6 @@
 # ADR-0079: The record display-name contract — `nameField` is the one canonical primary-title pointer
 
-**Status**: Accepted — implemented. **This file is a RETROACTIVE RECONSTRUCTION written 2026-08-08**, not a contemporaneous record; see [Provenance](#provenance-read-this-before-citing-this-file) before you cite it.
+**Status**: Accepted — implemented. **This file is a RETROACTIVE RECONSTRUCTION written 2026-08-08**, not a contemporaneous record; see [Provenance](#provenance-read-this-before-citing-this-file) before you cite it. · **Amended** (2026-11-04, [#29506](https://github.com/objectstack-ai/objectstack/issues/29506), ruling of record [`6574393684`](https://github.com/objectstack-ai/objectstack/issues/29007#issuecomment-6574393684) on #29007, letter B) — `title-format-retired` is an error since PR #29499; see the note under D3.
 - **Decided**: 2026-06-28 (the decision), reconstructed 2026-08-08 (this file)
 - **Reconstructed by**: #6634
 - **Implemented by**: [#2434](https://github.com/objectstack-ai/objectstack/pull/2434) (foundation — `nameField` + resolver), [#2458](https://github.com/objectstack-ai/objectstack/pull/2458) (designate-only provisioning at the registry seam), [#2463](https://github.com/objectstack-ai/objectstack/pull/2463) (the author-time gate)
@@ -126,6 +126,18 @@ output, describe marks the old key deprecated."*
 
 ### D3 — `titleFormat` is retired in favour of `nameField`
 
+> **Amendment (2026-11-04, #29506).** The diagnostic is no longer advisory.
+> Under the ruling of record on #29007 (6574393684, letter B), PR #29499
+> (`3557366c02`) made `title-format-retired` an **error**: the metadata save
+> gate (`422 INVALID_METADATA` on an active save, a draft promotion and a
+> restore) and `os validate` / `os build` / `os lint` refuse an object that
+> declares `titleFormat`, and the fix is `nameField`. The key is refused, not
+> removed: the schema still parses it, so a stored object that carries it keeps
+> loading and reading until its next save. The decision below stands; the
+> "deprecated and lint-warned" and "advisory, not an error" sentences and their
+> citation describe the code before #29499, and D8's "never errors" no longer covers this rule
+> (`packages/lint/src/validate-record-title.ts`, `validateTitleFormatRetired`).
+
 `titleFormat` is deprecated and lint-warned, and an explicit `nameField` takes
 precedence over it. It **still parses** — existing metadata keeps loading — so
 the diagnostic is advisory, not an error:
@@ -222,6 +234,9 @@ seam (#2434's "Staged (deliberate)" section, kept as the `TODO(ADR-0079)` that
 
 ### D8 — The author-time gate is advisory by design
 
+> **Amended (2026-11-04, #29506).** `title-format-retired` is an error since #29499; see the
+> amendment under D3. This section's "never errors" and its quotation now describe `title-unresolvable` alone.
+
 `@objectstack/lint`'s `validate-record-title` reports two warnings —
 `title-format-retired` (D3) and `title-unresolvable` (`objectTitleCompleteness`
 returns `status: 'none'`) — and **never errors**:
 
@@ -87,7 +87,7 @@ the publish door rejects it before that:
 | `datasource` | `'default'` | Target datasource ID for virtualized data |
 | `nameField` | derived (e.g. `'name'`/`'title'`) | **Canonical** record-title field — the stored field used as the record's display name. Use a single text/email field; a composite title to import, sort or search by is a stored computed field (a non-`formula` field with an `expression`); a text formula is display-only |
 | `displayNameField` | — | **Deprecated** alias for `nameField` (still honored as a fallback) |
-| `titleFormat` | — | **Deprecated, not removed (ADR-0079)** — render-only: the server can't return or query it. Use `nameField` (it wins); a composite title follows the `nameField` row |
+| `titleFormat` | — | **Refused (ADR-0079)**: a save and `os validate` refuse it (`title-format-retired`). Move it to `nameField`; a composite title follows the `nameField` row |
 | `enable` | — | Capability flags (trackHistory, searchable, apiEnabled, etc.) |
 | `fieldGroups` | — | Ordered list of logical field groups for forms/detail pages (see [Field Groups](./references/examples-objects.md#field-groups-mvp)) |
 | `lifecycle` | `record` semantics (permanent) | Data retention/rotation/archival contract. **Required for append-only, high-write-rate objects** — a `telemetry`/`transient`/`event`/`audit` class must declare a bounding policy or parsing fails (see [Data Lifecycle & Retention](./rules/lifecycle.md)) |
 
@@ -456,11 +456,11 @@ a bare string (auto-wrapped) or their helper, and read the same variable scope.
 | Dialect | Helper | Grammar | Carriers |
 |:---|:---|:---|:---|
 | `cron` | `` cron`0 6 * * MON` `` | 5- or 6-field cron, or one of `@yearly` `@annually` `@monthly` `@weekly` `@daily` `@hourly` `@reboot` | `Job.schedule.expression` (canonical) |
-| `template` | `` tmpl`Hello {{ record.first_name }}` `` | `{{ path }}` or `{{ path \| formatter[:arg] }}` — double braces only, no conditionals; the formatter whitelist is `TEMPLATE_FORMATTERS`, exported from `@objectstack/formula` | `system/email-template` `subject` / `bodyHtml` / `bodyText`, `ai/model-registry` `promptTemplate.system` / `.user`, `Object.titleFormat` (deprecated → `nameField`, ADR-0079) |
+| `template` | `` tmpl`Hello {{ record.first_name }}` `` | `{{ path }}` or `{{ path \| formatter[:arg] }}` — double braces only, no conditionals; the formatter whitelist is `TEMPLATE_FORMATTERS`, exported from `@objectstack/formula` | `system/email-template` `subject` / `bodyHtml` / `bodyText`, `ai/model-registry` `promptTemplate.system` / `.user`, `Object.titleFormat` (a save and `os validate` refuse it; move it to `nameField`, ADR-0079) |
 
 `shared/expression.zod.ts` declares both surfaces and their carriers.
-Missing template paths render as the empty string. Move logic into a CEL field:
-a template holds a path and a formatter, nothing else. A `currency` argument is a
+Missing template paths render as the empty string. Move logic into a CEL field.
+A `currency` argument is a
 literal code (`currency:EUR`); only an email template may read it from the send's
 data instead, `{{ amount | currency:@currency_code }}`.