@@ -0,0 +1,14 @@
+---
+"@objectstack/spec": patch
+---
+
+`TemplateExpressionInputSchema` documents what the `template` dialect actually accepts, instead of illustrating it with a grammar it does not judge.
+
+The docblock introduced the dialect as "anything with `{{var}}` interpolation". Nothing in the schema enforces that: `TemplateExpressionInputSchema` judges the dialect tag and non-emptiness and nothing else, and the same docblock already said so one clause later. Read as a declaration, it made every single-brace `titleFormat` value in the wild look like it was crossing a gate. There is no gate.
+
+The corrected prose states where the placeholder grammar really lives — with the renderer that consumes the slot — and that the two spellings in circulation are not interchangeable everywhere:
+
+- `{{var}}` is the canonical form and the only one the registered `template` engine reads (`@objectstack/formula`'s `templateEngine`); the messaging renderer, the email plugin and the i18n adapters match it alone and leave a `{var}` in their output verbatim.
+- `titleFormat` is the exception: its renderers accept `{{var}}` and `{var}` as equivalent, normalizing the double form down to the single one before substituting. Single-brace `titleFormat` values are legal by construction, not a grammar the schema failed to enforce.
+
+`titleFormat`'s `.describe()` says the same thing at the slot. Documentation only — the schema's judging logic, its accept-set and its exports are untouched, so nothing an author can write changes meaning. Both strings publish (`dist/*.d.ts` and the bundled `.describe()`), which is why this is a `patch` rather than a `skip-changeset`.
@@ -787,7 +787,7 @@ Metadata query with filtering, sorting, and pagination
 | **activityMilestones** | `{ field: string; value: string; summary: string; type?: string }[]` | optional | Declarative semantic activity milestones — emit a templated timeline row when a field transitions into a value, no hook code (ADR-0052 §5b.2). |
 | **nameField** | `string` | optional | [ADR-0079] Canonical primary title field — the stored field used as the record display name (e.g. "name", "title"). |
 | **displayNameField** | `string` | optional | [DEPRECATED → nameField] Field to use as the record display name (e.g., "name", "title"). Accepted as an alias for nameField. |
-| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. |
+| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. Placeholders may be written `{{field}}` or `{field}` — the title renderers treat the two as equivalent, normalizing `{{field}}` to `{field}` before substituting; neither spelling is judged at parse time. |
 | **highlightFields** | `string[]` | optional | [ADR-0085] Ordered most-important fields; first entry wins where only one fits. Drives default columns, cards, previews, detail highlight strip. Renamed from compactLayout. |
 | **stageField** | `string \| false` | optional | [ADR-0085] Lifecycle stage field (linear/ordered), or false to declare the status field non-linear and suppress stage heuristics. Absent = heuristic detection allowed. |
 | **editMode** | `Enum<'modal' \| 'page'>` | optional | Edit-interaction intent for records of this object: 'modal' opens the edit form as a dialog over the current view; 'page' navigates to a dedicated full-page edit route. Absent = the renderer picks its own default (objectui defaults to modal). Cross-renderer intent, not pixel styling (family). |
 
@@ -162,7 +162,7 @@ const result = ApiMethod.parse(data);
 | **activityMilestones** | `{ field: string; value: string; summary: string; type?: string }[]` | optional | Declarative semantic activity milestones — emit a templated timeline row when a field transitions into a value, no hook code (ADR-0052 §5b.2). |
 | **nameField** | `string` | optional | [ADR-0079] Canonical primary title field — the stored field used as the record display name (e.g. "name", "title"). |
 | **displayNameField** | `string` | optional | [DEPRECATED → nameField] Field to use as the record display name (e.g., "name", "title"). Accepted as an alias for nameField. |
-| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. |
+| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. Placeholders may be written `{{field}}` or `{field}` — the title renderers treat the two as equivalent, normalizing `{{field}}` to `{field}` before substituting; neither spelling is judged at parse time. |
 | **highlightFields** | `string[]` | optional | [ADR-0085] Ordered most-important fields; first entry wins where only one fits. Drives default columns, cards, previews, detail highlight strip. Renamed from compactLayout. |
 | **stageField** | `string \| false` | optional | [ADR-0085] Lifecycle stage field (linear/ordered), or false to declare the status field non-linear and suppress stage heuristics. Absent = heuristic detection allowed. |
 | **editMode** | `Enum<'modal' \| 'page'>` | optional | Edit-interaction intent for records of this object: 'modal' opens the edit form as a dialog over the current view; 'page' navigates to a dedicated full-page edit route. Absent = the renderer picks its own default (objectui defaults to modal). Cross-renderer intent, not pixel styling (family). |
 
@@ -22,7 +22,7 @@ envelope.
 |:---|:---|:---|
 | `cel`      | `@objectstack/formula` (cel-js + ObjectStack stdlib) | formulas, predicates, seed dynamic values |
 | `cron`     | none at parse time — `croner` fires it at schedule time, on the one wired slot | job schedules |
-| `template` | `{{var}}` interpolation at evaluate time (same variable scope as CEL) | notification subjects/bodies, `titleFormat`, prompt templates |
+| `template` | placeholder interpolation at evaluate time (same variable scope as CEL); canonically `{{var}}`, but the accepted spelling belongs to the renderer, not to this schema — see `TemplateExpressionInputSchema` | notification subjects/bodies, `titleFormat`, prompt templates |
 
 No cron syntax is judged at parse time: `croner` evaluates a cron slot only
 when `CronSchedule.expression` is scheduled (`toBoundaryJobSchedule` →
 
@@ -338,7 +338,7 @@ Create a new object
 | **activityMilestones** | `{ field: string; value: string; summary: string; type?: string }[]` | optional | Declarative semantic activity milestones — emit a templated timeline row when a field transitions into a value, no hook code (ADR-0052 §5b.2). |
 | **nameField** | `string` | optional | [ADR-0079] Canonical primary title field — the stored field used as the record display name (e.g. "name", "title"). |
 | **displayNameField** | `string` | optional | [DEPRECATED → nameField] Field to use as the record display name (e.g., "name", "title"). Accepted as an alias for nameField. |
-| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. |
+| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. Placeholders may be written `{{field}}` or `{field}` — the title renderers treat the two as equivalent, normalizing `{{field}}` to `{field}` before substituting; neither spelling is judged at parse time. |
 | **highlightFields** | `string[]` | optional | [ADR-0085] Ordered most-important fields; first entry wins where only one fits. Drives default columns, cards, previews, detail highlight strip. Renamed from compactLayout. |
 | **stageField** | `string \| false` | optional | [ADR-0085] Lifecycle stage field (linear/ordered), or false to declare the status field non-linear and suppress stage heuristics. Absent = heuristic detection allowed. |
 | **editMode** | `Enum<'modal' \| 'page'>` | optional | Edit-interaction intent for records of this object: 'modal' opens the edit form as a dialog over the current view; 'page' navigates to a dedicated full-page edit route. Absent = the renderer picks its own default (objectui defaults to modal). Cross-renderer intent, not pixel styling (family). |
@@ -622,7 +622,7 @@ Create a new object
 | **activityMilestones** | `{ field: string; value: string; summary: string; type?: string }[]` | optional | Declarative semantic activity milestones — emit a templated timeline row when a field transitions into a value, no hook code (ADR-0052 §5b.2). |
 | **nameField** | `string` | optional | [ADR-0079] Canonical primary title field — the stored field used as the record display name (e.g. "name", "title"). |
 | **displayNameField** | `string` | optional | [DEPRECATED → nameField] Field to use as the record display name (e.g., "name", "title"). Accepted as an alias for nameField. |
-| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. |
+| **titleFormat** | `string \| { dialect: 'template'; source?: string; ast?: any; meta?: object }` | optional | [DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. Placeholders may be written `{{field}}` or `{field}` — the title renderers treat the two as equivalent, normalizing `{{field}}` to `{field}` before substituting; neither spelling is judged at parse time. |
 | **highlightFields** | `string[]` | optional | [ADR-0085] Ordered most-important fields; first entry wins where only one fits. Drives default columns, cards, previews, detail highlight strip. Renamed from compactLayout. |
 | **stageField** | `string \| false` | optional | [ADR-0085] Lifecycle stage field (linear/ordered), or false to declare the status field non-linear and suppress stage heuristics. Absent = heuristic detection allowed. |
 | **editMode** | `Enum<'modal' \| 'page'>` | optional | Edit-interaction intent for records of this object: 'modal' opens the edit form as a dialog over the current view; 'page' navigates to a dedicated full-page edit route. Absent = the renderer picks its own default (objectui defaults to modal). Cross-renderer intent, not pixel styling (family). |
 
@@ -2119,7 +2119,7 @@ const ObjectSchemaBase = strictObject(
    * cross-repo back-compat). New metadata should set `nameField`.
    */
   displayNameField: z.string().optional().describe('[DEPRECATED → nameField] Field to use as the record display name (e.g., "name", "title"). Accepted as an alias for nameField.'),
-  titleFormat: TemplateExpressionInputSchema.optional().describe('[DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField.'),
+  titleFormat: TemplateExpressionInputSchema.optional().describe('[DEPRECATED → nameField (ADR-0079)] Render-only title template; the server cannot return or query it, and an explicit nameField now takes precedence. Migrate a single-field title to nameField, a composite to a formula field designated as nameField. Placeholders may be written {{field}} or {field} — the title renderers treat the two as equivalent, normalizing {{field}} to {field} before substituting; neither spelling is judged at parse time.'),
   /**
    * [ADR-0085] Semantic role: the object's most important fields, in priority
    * order (the first entry wins wherever only one field fits, e.g. child-record
 
@@ -20,7 +20,7 @@ import { z } from 'zod';
  * |:---|:---|:---|
  * | `cel`      | `@objectstack/formula` (cel-js + ObjectStack stdlib) | formulas, predicates, seed dynamic values |
  * | `cron`     | none at parse time — `croner` fires it at schedule time, on the one wired slot | job schedules |
- * | `template` | `{{var}}` interpolation at evaluate time (same variable scope as CEL) | notification subjects/bodies, `titleFormat`, prompt templates |
+ * | `template` | placeholder interpolation at evaluate time (same variable scope as CEL); canonically `{{var}}`, but the accepted spelling belongs to the renderer, not to this schema — see `TemplateExpressionInputSchema` | notification subjects/bodies, `titleFormat`, prompt templates |
  *
  * No cron syntax is judged at parse time: `croner` evaluates a cron slot only
  * when `CronSchedule.expression` is scheduled (`toBoundaryJobSchedule` →
@@ -283,7 +283,27 @@ export type CronExpressionInput = z.input<typeof CronExpressionInputSchema>;
  * naming the fix (`TYPED_EXPRESSION_DIALECT_ONLY.template`), as is a blank
  * string (`TYPED_EXPRESSION_SOURCE_REQUIRED.template`). Use this for
  * notification subjects/bodies, titleFormat, prompt templates — anything with
- * `{{var}}` interpolation. No template syntax is judged at parse time.
+ * placeholder interpolation.
+ *
+ * No template syntax is judged at parse time: this schema judges the dialect
+ * tag and non-emptiness and nothing else, so it declares no placeholder
+ * grammar and refuses no spelling. Which spelling actually interpolates
+ * belongs to the CONSUMING RENDERER, and the two spellings in use are not
+ * interchangeable everywhere:
+ *
+ * - `{{var}}` is the canonical form and the only one the registered `template`
+ *   engine reads (`@objectstack/formula`'s `templateEngine`); the messaging,
+ *   email and i18n renderers match it alone and leave a `{var}` in their
+ *   output verbatim.
+ * - `titleFormat` is the exception: its renderers take `{{var}}` and `{var}`
+ *   as equivalent, normalizing the double form down to the single one before
+ *   substituting (objectui's `formatTitleTemplate`, and the title renderer in
+ *   `@objectstack/metadata-protocol`). Both spellings resolve identically
+ *   there — single-brace `titleFormat` values are legal by construction, not
+ *   a grammar this schema failed to enforce.
+ *
+ * So write `{{var}}` unless the slot's renderer is known to normalize, and do
+ * not read either spelling as declared, preferred or rejected here.
  */
 export const TemplateExpressionInputSchema = z.union([
   typedExpressionStringArm('template'),