@@ -0,0 +1,18 @@
+---
+'@objectstack/spec': minor
+---
+
+Clause-②: yes (widening)
+
+The platform translation bundle (`PlatformTranslationDataSchema`) gains a slot for a settings
+`info_banner` row: `settings.<namespace>.banners.<banner_id>.title` and `.text`, keyed by the
+specifier's `id`, beside `groups`, `keys` and `actions`. `title` translates the specifier's `label`
+(the heading spelling `groups` already uses) and `text` translates its `bannerText` (markdown).
+Before this, a translated banner was refused with `unrecognized_keys`, so a banner reached every
+locale in its manifest English. The slot is strict: a borrowed `label`, `bannerText` or
+`description` leaf, or a singular `banner` group, is refused with the spelling it meant.
+
+Two resolvers read it, `resolveSettingsBannerTitle` and `resolveSettingsBannerText`, from the
+`resolveSettings*` family: they walk the requested locale and the declared fallback chain, then
+return the manifest literal. The `info_banner` specifier's own accept set is unchanged. Give the
+banner an `id` to make it addressable; a banner without one keeps rendering its literals.
@@ -287,6 +287,7 @@ Translation data for a single object
 | **groups** | `Record<string, { title?: string; description?: string }>` | optional | Group translations keyed by group key |
 | **keys** | `Record<string, { label?: string; help?: string; placeholder?: string; options?: Record<string, string> }>` | optional | Per-setting field translations keyed by setting key |
 | **actions** | `Record<string, { label?: string; confirmText?: string; successMessage?: string }>` | optional | Action button translations keyed by action id |
+| **banners** | `Record<string, { title?: string; text?: string }>` | optional | Info banner translations keyed by the info_banner specifier id |
 
 
 ---
 
@@ -19,4 +19,4 @@ hand-patch a number here** — fix the code or the verdict and regenerate.
 
 | Dir | Sites |
 |---|---|
-| `system/` | 373 |
+| `system/` | 374 |
@@ -855,6 +855,8 @@
     "resolveSettingsActionConfirm (function)",
     "resolveSettingsActionLabel (function)",
     "resolveSettingsActionSuccess (function)",
+    "resolveSettingsBannerText (function)",
+    "resolveSettingsBannerTitle (function)",
     "resolveSettingsDescription (function)",
     "resolveSettingsFieldHelp (function)",
     "resolveSettingsFieldLabel (function)",
 
@@ -816,6 +816,8 @@
     "resolveSettingsActionConfirm": "src/system/i18n-resolver.ts#resolveSettingsActionConfirm (function)",
     "resolveSettingsActionLabel": "src/system/i18n-resolver.ts#resolveSettingsActionLabel (function)",
     "resolveSettingsActionSuccess": "src/system/i18n-resolver.ts#resolveSettingsActionSuccess (function)",
+    "resolveSettingsBannerText": "src/system/i18n-resolver.ts#resolveSettingsBannerText (function)",
+    "resolveSettingsBannerTitle": "src/system/i18n-resolver.ts#resolveSettingsBannerTitle (function)",
     "resolveSettingsDescription": "src/system/i18n-resolver.ts#resolveSettingsDescription (function)",
     "resolveSettingsFieldHelp": "src/system/i18n-resolver.ts#resolveSettingsFieldHelp (function)",
     "resolveSettingsFieldLabel": "src/system/i18n-resolver.ts#resolveSettingsFieldLabel (function)",
 
@@ -3676,6 +3676,40 @@ export function resolveSettingsActionSuccess(
   );
 }
 
+/**
+ * Resolve an `info_banner` title under `settings.<namespace>.banners.<bannerId>.title`,
+ * keyed by the specifier's `id`; falls back to the specifier's `label`.
+ */
+export function resolveSettingsBannerTitle(
+  bundle: PlatformTranslationBundle | undefined,
+  namespace: string,
+  bannerId: string,
+  fallback: string,
+  opts?: ResolveOptions,
+): string {
+  return (
+    resolveOptionalString(bundle, namespace, (e) => e.banners?.[bannerId]?.title, opts)
+    ?? fallback
+  );
+}
+
+/**
+ * Resolve an `info_banner` body under `settings.<namespace>.banners.<bannerId>.text`,
+ * keyed by the specifier's `id`; falls back to the specifier's `bannerText`.
+ */
+export function resolveSettingsBannerText(
+  bundle: PlatformTranslationBundle | undefined,
+  namespace: string,
+  bannerId: string,
+  fallback: string | undefined,
+  opts?: ResolveOptions,
+): string | undefined {
+  return (
+    resolveOptionalString(bundle, namespace, (e) => e.banners?.[bannerId]?.text, opts)
+    ?? fallback
+  );
+}
+
 // ────────────────────────────────────────────────────────────────────────────
 // SettingsCommon — cross-namespace UI strings (source badges, etc.)
 // ────────────────────────────────────────────────────────────────────────────
 
@@ -0,0 +1,79 @@
+// Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
+
+import { describe, it, expect } from 'vitest';
+import { PlatformTranslationDataSchema, type PlatformTranslationBundle } from './translation.zod';
+import { resolveSettingsBannerText, resolveSettingsBannerTitle } from './i18n-resolver';
+
+/**
+ * The `info_banner` slot of the platform settings translation group:
+ * `settings.<namespace>.banners.<banner_id>.{title,text}`, keyed by the
+ * specifier's `id`, beside `groups` / `keys` / `actions`.
+ */
+describe('settings.<namespace>.banners — the info_banner translation slot', () => {
+  const banners = {
+    beta_notice: { title: '注意', text: 'Beta 功能可能随时变更。' },
+  };
+
+  it('accepts a banner title and text on the platform face', () => {
+    const result = PlatformTranslationDataSchema.safeParse({ settings: { feature_flags: { banners } } });
+    expect(result.success).toBe(true);
+  });
+
+  it.each([
+    ['the specifier spelling `bannerText`', { bannerText: 'x' }, 'text'],
+    ['the specifier spelling `label`', { label: 'x' }, 'title'],
+    ['the group body spelling `description`', { description: 'x' }, 'text'],
+  ])('refuses %s on a banner and names the leaf that holds it', (_what, leaf, expected) => {
+    const result = PlatformTranslationDataSchema.safeParse({
+      settings: { feature_flags: { banners: { beta_notice: leaf } } },
+    });
+    expect(result.success).toBe(false);
+    const issue = result.error?.issues.find((i) => i.code === 'unrecognized_keys');
+    expect(issue?.path).toEqual(['settings', 'feature_flags', 'banners', 'beta_notice']);
+    expect(issue?.message).toContain(`→ \`${expected}\``);
+  });
+
+  it('refuses the singular `banner` group and names `banners`', () => {
+    const result = PlatformTranslationDataSchema.safeParse({
+      settings: { feature_flags: { banner: banners } },
+    });
+    expect(result.success).toBe(false);
+    const issue = result.error?.issues.find((i) => i.code === 'unrecognized_keys');
+    expect(issue?.path).toEqual(['settings', 'feature_flags']);
+    expect(issue?.message).toContain('→ `banners`');
+  });
+});
+
+describe('resolveSettingsBannerTitle / resolveSettingsBannerText', () => {
+  const bundle: PlatformTranslationBundle = {
+    'zh-CN': {
+      settings: {
+        feature_flags: { banners: { beta_notice: { title: '注意', text: 'Beta 功能可能随时变更。' } } },
+      },
+    },
+  };
+
+  it('resolves the requested locale', () => {
+    const opts = { locale: 'zh-CN' };
+    expect(resolveSettingsBannerTitle(bundle, 'feature_flags', 'beta_notice', 'Heads up', opts)).toBe('注意');
+    expect(resolveSettingsBannerText(bundle, 'feature_flags', 'beta_notice', 'Beta features…', opts))
+      .toBe('Beta 功能可能随时变更。');
+  });
+
+  it('walks the declared fallback chain when the requested locale has no entry', () => {
+    const opts = { locale: 'ja-JP', fallbackChain: ['zh-CN'] };
+    expect(resolveSettingsBannerTitle(bundle, 'feature_flags', 'beta_notice', 'Heads up', opts)).toBe('注意');
+    expect(resolveSettingsBannerText(bundle, 'feature_flags', 'beta_notice', 'Beta features…', opts))
+      .toBe('Beta 功能可能随时变更。');
+  });
+
+  it('falls back to the manifest literal when no locale in the chain has the banner', () => {
+    const opts = { locale: 'ja-JP' };
+    expect(resolveSettingsBannerTitle(bundle, 'feature_flags', 'beta_notice', 'Heads up', opts)).toBe('Heads up');
+    expect(resolveSettingsBannerText(bundle, 'feature_flags', 'beta_notice', 'Beta features…', opts))
+      .toBe('Beta features…');
+    expect(resolveSettingsBannerText(bundle, 'feature_flags', 'other_notice', undefined, { locale: 'zh-CN' }))
+      .toBeUndefined();
+    expect(resolveSettingsBannerTitle(undefined, 'feature_flags', 'beta_notice', 'Heads up')).toBe('Heads up');
+  });
+});
@@ -393,8 +393,10 @@ export const SpecifierSchema = lazySchema(() => z.object({
   /**
    * Stable identifier (snake_case) used for i18n translation lookup,
    * action routing, and test selectors. Orthogonal to `key` (which is
-   * the storage path). Recommended for `group` and `action_button`
-   * specifiers so their labels can be translated and so action
+   * the storage path). Recommended for `group`, `info_banner` and
+   * `action_button` specifiers so their text can be translated
+   * (`settings.<namespace>.groups.<id>`, `.banners.<id>` and
+   * `.actions.<id>` in the platform translation bundle) and so action
    * handlers have stable hook keys. Must be unique within a manifest.
    */
   id: SnakeCaseIdentifierSchema.optional().describe('Stable identifier (snake_case)'),
 
@@ -1626,11 +1626,20 @@ const platformSettingsShape = () => ({
    *   settings.<namespace>.actions.<action_id>.label
    *   settings.<namespace>.actions.<action_id>.confirmText
    *   settings.<namespace>.actions.<action_id>.successMessage
+   *   settings.<namespace>.banners.<banner_id>.title
+   *   settings.<namespace>.banners.<banner_id>.text
+   *
+   * `banners` is keyed by an `info_banner` specifier's `id`, as `groups` is
+   * keyed by a `group` specifier's. Its leaves follow the nearest sibling:
+   * the specifier's `label` translates as `title` (the heading spelling
+   * `groups` already uses for the same field), and its `bannerText` as
+   * `text`. A banner without an `id` has no address here and renders its
+   * manifest literals.
    */
   settings: z.record(z.string(), strictObject({
     surface: 'this settings manifest translation',
     history: TRANSLATION_HISTORY,
-    aliases: { label: 'title', name: 'title', sections: 'groups', fields: 'keys', settings: 'keys' },
+    aliases: { label: 'title', name: 'title', sections: 'groups', fields: 'keys', settings: 'keys', banner: 'banners', notices: 'banners', alerts: 'banners' },
   }, {
     title: z.string().optional().describe('Translated settings manifest title'),
     description: z.string().optional().describe('Translated settings manifest description'),
@@ -1669,6 +1678,17 @@ const platformSettingsShape = () => ({
       confirmText: z.string().optional().describe('Translated confirmation prompt'),
       successMessage: z.string().optional().describe('Translated success toast/message'),
     })).optional().describe('Action button translations keyed by action id'),
+    banners: z.record(z.string(), strictObject({
+      surface: 'this settings banner translation',
+      history: TRANSLATION_HISTORY,
+      // The specifier's own spellings (`label`, `bannerText`) and the group
+      // body's (`description`) are the likely borrowings; each names the leaf
+      // that holds the same string here.
+      aliases: { label: 'title', name: 'title', heading: 'title', bannerText: 'text', body: 'text', description: 'text', message: 'text' },
+    }, {
+      title: z.string().optional().describe('Translated banner title (the info_banner specifier label)'),
+      text: z.string().optional().describe('Translated banner body, markdown (the info_banner specifier bannerText)'),
+    })).optional().describe('Info banner translations keyed by the info_banner specifier id'),
   })).optional().describe('Settings manifest translations keyed by namespace'),
 });