@@ -0,0 +1,26 @@
+---
+'@objectstack/spec': minor
+---
+
+feat(spec)!: `@objectstack/spec/shared` no longer exports `normalizeVisibleWhen` or `VISIBILITY_ALIAS_KEYS`; read `visibleWhen` directly
+
+Clause-②: yes (narrowing)
+
+**BREAKING (TS/API surface):** two exports of `@objectstack/spec/shared` are gone — the function `normalizeVisibleWhen`, which folded the retired `visibleOn` / `visibility` keys onto the canonical `visibleWhen`, and the const `VISIBILITY_ALIAS_KEYS`, which listed those two keys. Use `visibleWhen` directly instead: it is the one conditional-visibility key, and since 18 every schema that had the two old keys (the form field, the form section and the page component) refuses them by name. No schema used the fold after those keys retired, and no caller of either export was found in this repository or in the pinned renderer.
+
+## FROM → TO
+
+| you wrote | write instead |
+| --- | --- |
+| `import { normalizeVisibleWhen } from '@objectstack/spec/shared'`, then `normalizeVisibleWhen(node)` | read and write `node.visibleWhen`; there is no alias left to fold |
+| `import { VISIBILITY_ALIAS_KEYS } from '@objectstack/spec/shared'` | nothing — the two keys it named are refused by the schemas; to reject them yourself, parse with the schema |
+
+**The one-line fix:** delete the import and the call, and read `visibleWhen`.
+
+This supersedes the sentence in this release's `visibleOn` / `visibility` retirement note that says the two exports "stay exported": they leave in the same release.
+
+**What an author who still imports them sees:** `tsc` fails with TS2305 (`Module '"@objectstack/spec/shared"' has no exported member …`); an ESM named import fails at link time with a `SyntaxError` (the module does not provide an export of that name); a CommonJS `require` reads the member as `undefined`.
+
+**Nothing to migrate in metadata.** No authored document ever carried either export, so `os migrate meta` has nothing to visit. The stored-row conversions `view-visibleOn-to-visibleWhen` and `page-component-visibility-to-visibleWhen` are unchanged: a pre-18 `sys_metadata` view or page row that still carries an old key keeps loading with `visibleWhen`.
+
+<!-- adr-0087: registered visibility-alias-fold-unexported -->
@@ -96,7 +96,6 @@
     "TemplateExpressionInput (type)",
     "TemplateExpressionInputSchema (const)",
     "TypedExpressionDialect (type)",
-    "VISIBILITY_ALIAS_KEYS (const)",
     "ValueDomain (type)",
     "ValueDomainSchema (const)",
     "applyProtection (function)",
@@ -116,7 +115,6 @@
     "normalizeMetadataCollection (function)",
     "normalizePluginMetadata (function)",
     "normalizeStackInput (function)",
-    "normalizeVisibleWhen (function)",
     "objectStackErrorMap (const)",
     "pluralToSingular (function)",
     "renderDiffMessage (function)",
 
@@ -91,7 +91,6 @@
     "TemplateExpressionInput": "src/shared/expression.zod.ts#TemplateExpressionInput (type)",
     "TemplateExpressionInputSchema": "src/shared/expression.zod.ts#TemplateExpressionInputSchema (const)",
     "TypedExpressionDialect": "src/shared/expression.zod.ts#TypedExpressionDialect (type)",
-    "VISIBILITY_ALIAS_KEYS": "src/shared/visibility.ts#VISIBILITY_ALIAS_KEYS (const)",
     "ValueDomain": "src/shared/value-domain.zod.ts#ValueDomain (type)",
     "ValueDomainSchema": "src/shared/value-domain.zod.ts#ValueDomainSchema (const)",
     "applyProtection": "src/shared/protection.zod.ts#applyProtection (function)",
@@ -111,7 +110,6 @@
     "normalizeMetadataCollection": "src/shared/metadata-collection.zod.ts#normalizeMetadataCollection (function)",
     "normalizePluginMetadata": "src/shared/metadata-collection.zod.ts#normalizePluginMetadata (function)",
     "normalizeStackInput": "src/shared/metadata-collection.zod.ts#normalizeStackInput (function)",
-    "normalizeVisibleWhen": "src/shared/visibility.ts#normalizeVisibleWhen (function)",
     "objectStackErrorMap": "src/shared/error-map.zod.ts#objectStackErrorMap (const)",
     "pluralToSingular": "src/meta-spelling/manifest-collection-spelling.ts#pluralToSingular (function)",
     "renderDiffMessage": "src/shared/external-errors.ts#renderDiffMessage (function)",
 
@@ -7,7 +7,7 @@ import type { KeySetGuidance } from '../shared/suggestions.zod';
 // Package-internal, like `strict-object` itself — the `shared/index.ts` barrel
 // deliberately does not re-export it, so nothing about the public API surface
 // moves. No cycle back into this file: that module's only runtime import is
-// `shared/visibility.ts`, which imports nothing at runtime.
+// `shared/visibility-strict-options.ts`, which imports nothing at runtime.
 import { SELECT_OPTION_EDITABILITY_GUIDANCE } from '../shared/editability-boundary';
 import { MetadataProtectionFields } from '../kernel/metadata-protection.zod';
 // The ADR-0078 completeness predicate the choice door below applies, read
 
@@ -317,9 +317,10 @@ type WithRequiresFeature = {
 
 /**
  * Lower the declarative `requiresFeature: '<flag>'` sugar into the canonical
- * `visible` CEL predicate and strip the sugar key from the output — mirroring
- * `normalizeVisibleWhen` (ADR-0089): persisted artifacts, lint, runtime, and
- * objectui only ever see the canonical envelope.
+ * `visible` CEL predicate and strip the sugar key from the output — the same
+ * schema-boundary fold onto one canonical key that ADR-0089 ran for
+ * `visibleOn` / `visibility` → `visibleWhen` through 17: persisted artifacts,
+ * lint, runtime, and objectui only ever see the canonical envelope.
  *
  * - No existing `visible` → `{ dialect: 'cel', source: <gate> }`, string-equal
  *   to the hand-written gates it replaces.
 
@@ -0,0 +1,35 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+import type { SemanticMigration } from '../../types.js';
+
+// A TS/API surface, never stored in stack metadata: there is no source for the
+// chain to rewrite, so this entry is the whole ADR-0087 registration. The two
+// stored-row conversions that rename the retired keys on a pre-18 `sys_metadata`
+// row (`view-visibleOn-to-visibleWhen`, `page-component-visibility-to-visibleWhen`)
+// are a different mechanism and are not touched by this removal.
+export const entry: SemanticMigration = {
+  id: 'visibility-alias-fold-unexported',
+  surface:
+    '`normalizeVisibleWhen` (function) and `VISIBILITY_ALIAS_KEYS` (const) on '
+    + '`@objectstack/spec/shared` — the fold of the retired `visibleOn` / `visibility` '
+    + 'keys onto the canonical `visibleWhen` (ADR-0089 D2), and the list of those two keys',
+  replacement:
+    '(removed from the public surface — no replacement export. Read and write `visibleWhen` '
+    + 'directly: it is the one conditional-visibility key every schema accepts, and the form '
+    + 'field, form section and page component shapes refuse `visibleOn` and `visibility` by '
+    + 'name with the rename as the prescription. A pre-18 document carrying either key is '
+    + 'renamed by hand; a stored row is renamed by the rehydration conversions.)',
+  reason:
+    'ADR-0049 enforce-or-remove applied to an export. Since the two alias keys retired at 18, '
+    + 'no schema calls the fold, and a measured search of this repository and of the pinned '
+    + 'renderer found no caller of either export, only comments. A published helper that '
+    + 'quietly re-accepts two keys every parsing door refuses invites exactly the consumer-side '
+    + 'tolerance the contract-first rule forbids: a renderer calling it would honour `visibleOn` '
+    + 'where the spec rejects it.',
+  acceptanceCriteria:
+    'No code imports `normalizeVisibleWhen` or `VISIBILITY_ALIAS_KEYS` from '
+    + '`@objectstack/spec/shared` or any other entry (TS2305 after upgrade). Every '
+    + 'visibility-carrying shape parses and refuses exactly as before — no schema used the '
+    + 'fold. No authored metadata document ever carried either export, so `os migrate meta` '
+    + 'has nothing to visit.',
+};
@@ -13,8 +13,9 @@ export const entry: SemanticMigration = {
     '(removed from the public surface — no replacement export. It was an internal option bag '
     + 'for this package\'s own schemas; the visibility contract it configures is unchanged and '
     + 'still published through the schemas that use it — `FormFieldSchema`, `FormSectionSchema` '
-    + 'and the page component — together with `normalizeVisibleWhen` and '
-    + '`VISIBILITY_ALIAS_KEYS`, which stay exported.)',
+    + 'and the page component. The alias fold `normalizeVisibleWhen` and its key list '
+    + '`VISIBILITY_ALIAS_KEYS` are removed from the same entry in 18 as well (the D3 entry '
+    + '`visibility-alias-fold-unexported`).)',
   reason:
     'ADR-0049 enforce-or-remove applied to an export. The const was barrel-exported while its '
     + 'type, `StrictObjectOptions`, is deliberately unpublished, so no consumer could annotate it, '
 
@@ -29,7 +29,6 @@ export * from './metadata-collection.zod';
 export * from './metadata-url-spelling';
 export * from './lazy-schema';
 export * from './expression.zod';
-export * from './visibility';
 export * from './protection.zod';
 export * from './resilient-fetch';
 // The closed standard-domain vocabulary (`iana_time_zone` / `iso_4217_currency`
 
@@ -0,0 +1,35 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * `@objectstack/spec/shared` no longer exports the ADR-0089 alias fold.
+ *
+ * `normalizeVisibleWhen` folded the retired `visibleOn` / `visibility` keys onto
+ * the canonical `visibleWhen`, and `VISIBILITY_ALIAS_KEYS` listed those two keys.
+ * Once both keys became `retiredKey()` tombstones at 18, no schema called the
+ * fold and no consumer in either repository did. A published helper that
+ * re-accepts what every parsing door refuses is an invitation to consumer-side
+ * tolerance, so both left the surface (ADR-0087 D3 entry
+ * `visibility-alias-fold-unexported`). The replacement is to read `visibleWhen`
+ * directly.
+ *
+ * Read from the barrel the `./shared` subpath export compiles, through the
+ * runtime namespace, with a surviving export as the lit control that the
+ * namespace is really populated.
+ */
+
+import { describe, it, expect } from 'vitest';
+import * as shared from './index';
+
+describe('`./index` (the `@objectstack/spec/shared` surface)', () => {
+  it('still exports its surviving members (the control)', () => {
+    expect(typeof shared.lazySchema).toBe('function');
+    expect('lazySchema' in (shared as Record<string, unknown>)).toBe(true);
+  });
+
+  it.each(['normalizeVisibleWhen', 'VISIBILITY_ALIAS_KEYS'])(
+    'no longer exports `%s`',
+    (name) => {
+      expect(name in (shared as Record<string, unknown>)).toBe(false);
+    },
+  );
+});