diff --git a/locales/rn/de.json b/locales/rn/de.json
index 7c8e1686..f810eca3 100644
--- a/locales/rn/de.json
+++ b/locales/rn/de.json
@@ -952,6 +952,7 @@
       "not_empty_message": "\"{name}\" enthält {count} E-Mails. Trotzdem löschen?",
       "not_empty_title": "Ordner nicht leer",
       "own_account": "Meine Ordner",
+      "parent_folder": "Übergeordneter Ordner",
       "role": "Ordnerrolle",
       "role_hint": "Weisen Sie diesem Ordner eine Sonderrolle zu (Archiv, Spam, …). Jede Rolle kann nur einem Ordner zugewiesen werden.",
       "save_failed": "Speichern fehlgeschlagen",
diff --git a/locales/rn/en.json b/locales/rn/en.json
index fb90bce8..8b53ba9e 100644
--- a/locales/rn/en.json
+++ b/locales/rn/en.json
@@ -1237,6 +1237,7 @@
       "not_empty_message": "\"{name}\" contains {count} emails. Delete anyway?",
       "not_empty_title": "Folder not empty",
       "own_account": "My folders",
+      "parent_folder": "Parent folder",
       "role": "Special use",
       "role_hint": "Assign a special-use role (Archive, Junk, …) to this folder. Each role can be held by one folder.",
       "save_failed": "Save failed",
diff --git a/src/components/__tests__/placeholder-params.test.ts b/src/components/__tests__/placeholder-params.test.ts
new file mode 100644
index 00000000..5d39563e
--- /dev/null
+++ b/src/components/__tests__/placeholder-params.test.ts
@@ -0,0 +1,76 @@
+// A t() call whose catalog text has a {placeholder} but which passes no
+// values shows the placeholder as it is: the New folder sheet labelled its
+// parent picker with settings.folders.subfolder_of, the webmail's
+// "Inside {name}" hint, and read "Inside {name}". The English fallback in the
+// call ("Parent folder") hid it in review, since the catalog text wins.
+import { describe, expect, it, vi } from 'vitest';
+import fs from 'node:fs';
+import path from 'node:path';
+
+vi.mock('expo-localization', () => ({ getLocales: () => [] }));
+
+import { getDictionary } from '../../i18n';
+
+const SRC = path.resolve(__dirname, '../..');
+
+// The settings, filters, files and sheet code this check covers.
+const SCOPE = [
+  'components/settings',
+  'components/filters',
+  'components/files',
+  'components/Dialog.tsx',
+  'components/Input.tsx',
+  'components/RadioGroup.tsx',
+  'components/ToggleSwitch.tsx',
+  'components/TagSheet.tsx',
+  'components/NewTagRow.tsx',
+  'components/MoveSheet.tsx',
+  'components/IdentitySheet.tsx',
+  'components/TemplateSheet.tsx',
+  'screens/SettingsScreen.tsx',
+  'screens/FilesScreen.tsx',
+];
+
+function files(rel: string): string[] {
+  const p = path.join(SRC, rel);
+  if (!fs.statSync(p).isDirectory()) return [p];
+  return fs.readdirSync(p).flatMap((e) => (e === '__tests__' ? [] : files(path.join(rel, e))))
+    .filter((f) => /\.tsx?$/.test(f));
+}
+
+function flatten(obj: Record<string, unknown>, prefix = '', out = new Map<string, string>()): Map<string, string> {
+  for (const [k, v] of Object.entries(obj)) {
+    const key = prefix ? `${prefix}.${k}` : k;
+    if (v && typeof v === 'object') flatten(v as Record<string, unknown>, key, out);
+    else if (typeof v === 'string') out.set(key, v);
+  }
+  return out;
+}
+
+// t('key', 'fallback') or t('key', "fallback") closed right after the fallback.
+const CALL_WITHOUT_VALUES = /\btr?\(\s*'([^']+)'\s*,\s*('(?:[^'\\]|\\.)*'|"(?:[^"\\]|\\.)*")\s*,?\s*\)/g;
+// {name} or {count, plural, ...}; not the {{name}} template tokens.
+const PLACEHOLDER = /(?<!\{)\{\s*\w+\s*[,}]/;
+
+describe('t() calls without values', () => {
+  it('use catalog texts that have no placeholders', () => {
+    const en = flatten(getDictionary('en') as Record<string, unknown>);
+    const offenders: string[] = [];
+    for (const file of SCOPE.flatMap(files)) {
+      const source = fs.readFileSync(file, 'utf8');
+      for (const m of source.matchAll(CALL_WITHOUT_VALUES)) {
+        const text = en.get(m[1]);
+        if (text && PLACEHOLDER.test(text)) offenders.push(`${m[1]} = ${text} (${path.relative(SRC, file)})`);
+      }
+    }
+    expect(offenders).toEqual([]);
+  });
+
+  it('spots a call that leaves a placeholder unfilled', () => {
+    const calls = [..."t('settings.folders.subfolder_of', 'Parent folder')".matchAll(CALL_WITHOUT_VALUES)];
+    expect(calls.map((m) => m[1])).toEqual(['settings.folders.subfolder_of']);
+    expect(PLACEHOLDER.test('Inside {name}')).toBe(true);
+    expect(PLACEHOLDER.test('Placeholders: {{recipient_name}}')).toBe(false);
+    expect([..."t('a.b', 'x', { name })".matchAll(CALL_WITHOUT_VALUES)]).toEqual([]);
+  });
+});
diff --git a/src/components/settings/FolderSettings.tsx b/src/components/settings/FolderSettings.tsx
index 2268cb5e..f4878192 100644
--- a/src/components/settings/FolderSettings.tsx
+++ b/src/components/settings/FolderSettings.tsx
@@ -352,7 +352,8 @@ export function FolderSettings() {
               <Text style={styles.fieldLabel}>
                 {editor?.kind === 'edit'
                   ? t('settings.folders.move_under', 'Move under')
-                  : t('settings.folders.subfolder_of', 'Parent folder')}
+                  // Not subfolder_of: that is the webmail's "Inside {name}" hint.
+                  : t('settings.folders.parent_folder', 'Parent folder')}
               </Text>
               <Select
                 value={draftParent}