@@ -4,7 +4,7 @@
 
 feat(core): export the emptiness rule a `required` declaration is judged by — `isEmptyForRequired(def, value)` and `isMissing(value)`
 
-Clause-②: yes
+Clause-②: yes (widening)
 
 - **New exports from `@objectstack/core`'s `.` entry.** `isMissing(value)` is `true` for `undefined`, `null`, and a string that is empty or only whitespace. `isEmptyForRequired(def, value)` is `isMissing`, plus an empty list `[]` on a field whose DECLARED value is a set (`@objectstack/spec/data`'s `isMultiValueField`: `tags`, `multiselect`, `checkboxes`, or a `select` / `radio` / `lookup` / `user` / `file` / `image` field flagged `multiple: true`). `def` is a `ValueShapeFieldDef` (`{ type, multiple? }`). A structured-JSON field's `[]` is a document, not an empty value.
 - **Why it moved.** It was private to `@objectstack/objectql`'s record validator, where the object-level `required` check runs. `@objectstack/rest`'s anonymous public-form submit route now judges a FORM's `required` with it, and rest does not depend on the engine at runtime. So the one rule lives in the package both depend on, and the two doors call the same field missing.
 
@@ -4,7 +4,7 @@
 
 refactor(objectql): the record validator reads `isMissing` / `isEmptyForRequired` from `@objectstack/core` instead of private copies
 
-Clause-②: yes
+Clause-②: no
 
 - **No behaviour change.** The object-level `required` check, the `required_cleared` PATCH check, the blank-to-`null` normalisation of typed columns and the value-shape scan judge "missing" exactly as before; the private copies of the two predicates are deleted and `@objectstack/core`'s exports, moved there unchanged, are imported at every read site.
 - **Why:** `@objectstack/rest`'s public-form submit route now judges a form's `required` by the same rule, and it cannot import the engine.
@@ -2,11 +2,13 @@
 "@objectstack/rest": patch
 ---
 
-fix(rest): an anonymous public-form submit that leaves a form-required field empty answers `400 VALIDATION_FAILED` naming the field, and stores nothing
+fix(rest)!: an anonymous public-form submit that leaves a form-required field empty answers `400 VALIDATION_FAILED` naming the field, and stores nothing
 
-Clause-②: yes
+Clause-②: no (narrowing)
+
+<!-- adr-0087: not-required (no-migration-prescription) the narrowing is a runtime REST door's accept set, POST /forms/:slug/submit: no stored metadata changes shape and nothing must be rewritten, so `objectstack migrate meta` has nothing to do; a caller that omitted a form-required field sends it -->
 
 - **What changed.** `POST /forms/:slug/submit` now enforces the form's own `required`: a section entry `{ field: 'email', required: true }` is judged before the write, with the rule the engine's object-level check uses (`isEmptyForRequired` from `@objectstack/core`). A submission whose value for such a field is absent, `null`, `''`, only whitespace, or `[]` on a multi-value field is refused, and no row is created. Before, the engine judged only the fields the OBJECT requires, so a field only the form required answered `201` and was stored empty — while the rendered form refused the same submission.
 - **The refusal** is the object-level one's envelope on this route, key for key: `400` with top-level `code: 'VALIDATION_FAILED'`, `error` (the messages), and `fields[]` of `{ field, code: 'required', message, label }`, worded by the same validation catalog (for example `Email is required`). Every empty form-required field is named in one refusal, in the form's order.
-- **Narrowing — who it affects.** A script or integration that posts to a public form and omits a field the form marks `required: true` now gets `400` instead of `201`. The fix is to send that field, or to remove `required: true` from the form entry if the field is optional. Nothing that was refused before is accepted now.
+- **BREAKING — a narrowing, and who it affects.** A script or integration that posts to a public form and omits a field the form marks `required: true` now gets `400` instead of `201`. The fix is to send that field. Nothing that was refused before is accepted now.
 - **Judged only where the form asks.** An entry the form hides (`hidden: true`), or shows only conditionally (`visibleWhen` on the entry or on its section), is not judged — nothing server-side evaluates a form-view `visibleWhen`. A server-managed anchor (`owner_id`, `organization_id`, …) is never written by this route, so it is never judged. An object `defaultValue` or a `beforeInsert` hook does not satisfy a field the visitor omitted: the route judges what the visitor sent.