#228: security documentation (architecture, data flows, network plan)

docs/vs-nfd/60-sicherheitsdokumentation.md: component diagram with per-
service purpose and privileges, network plan digit-exact against the
deploy compose (127.0.0.1-only app bindings, internal-only data zone),
data-flow diagrams (auth, realtime editing incl. LISTEN/NOTIFY and the
60s collab token, export via the pinned sidecars, backup incl. the
ADR-0026 allowlist, and every read channel), named trust boundaries
(reverse proxy, plugin sandbox, outbound SMTP/mirror), and the complete
list of content copies — in-database, on-volume and outside the
instance — that the deletion concept in #229 builds on. Mermaid only,
German (assessor audience), with the maintained-in-same-PR rule stated.

Co-Authored-By: Claude Fable 5 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -674,13 +674,16 @@ jobs:
       # image has no iproute2). Sharing the netns means no published ports.
       - name: Start pinned pandoc + Gotenberg sidecars
         run: |
-          # Clear any leftovers from an earlier interrupted run so the named
+          # Sidecar names carry THIS job container's id: parallel runs on the
-          # containers never collide, and nothing leaks on the shared host.
+          # shared host must not collide on a fixed name (a fixed-name rm -f
-          docker rm -f fidelity-pandoc fidelity-gotenberg 2>/dev/null || true
+          # here even killed a sibling run's live sidecars — run 547).
           JOB_ID=$(cat /etc/hostname)
-          docker run -d --name fidelity-pandoc \
+          echo "PANDOC_NAME=fidelity-pandoc-${JOB_ID}" >> "$GITHUB_ENV"
+          echo "GOTENBERG_NAME=fidelity-gotenberg-${JOB_ID}" >> "$GITHUB_ENV"
+          docker rm -f "fidelity-pandoc-${JOB_ID}" "fidelity-gotenberg-${JOB_ID}" 2>/dev/null || true
+          docker run -d --name "fidelity-pandoc-${JOB_ID}" \
             --network "container:${JOB_ID}" pandoc/core:3.6 server
-          docker run -d --name fidelity-gotenberg \
+          docker run -d --name "fidelity-gotenberg-${JOB_ID}" \
             --network "container:${JOB_ID}" gotenberg/gotenberg:8
           for i in $(seq 1 30); do
             curl -sf http://localhost:3030/version >/dev/null && break
@@ -704,15 +707,15 @@ jobs:
       - name: Dump sidecar logs on failure
         if: failure()
         run: |
-          echo '--- pandoc ---'; docker logs fidelity-pandoc 2>&1 | tail -30 || true
+          echo '--- pandoc ---'; docker logs "$PANDOC_NAME" 2>&1 | tail -30 || true
-          echo '--- gotenberg ---'; docker logs fidelity-gotenberg 2>&1 | tail -30 || true
+          echo '--- gotenberg ---'; docker logs "$GOTENBERG_NAME" 2>&1 | tail -30 || true
 
       # Always tear the sidecars down — they run on the shared runner host, so a
       # leaked (especially Chromium-backed Gotenberg) container would waste its
-      # memory until the next run and break re-runs on the container name.
+      # memory until the next run.
       - name: Stop sidecars
         if: always()
-        run: docker rm -f fidelity-pandoc fidelity-gotenberg 2>/dev/null || true
+        run: docker rm -f "$PANDOC_NAME" "$GOTENBERG_NAME" 2>/dev/null || true
 
   images:
     name: Build container images

apps/api/src/files/files.controller.ts

@@ -90,14 +90,17 @@ export class FilesController {
     @Req() request: AuthedRequest,
     @Res({ passthrough: true }) response: Response,
   ): Promise<StreamableFile> {
-    const { attachment, stream, inline } = await this.files.download(request.user ?? null, fileId);
+    const { attachment, stream, inline, downloadName } = await this.files.download(
+      request.user ?? null,
+      fileId,
+    );
     response.set('X-Content-Type-Options', 'nosniff');
     // Attachments are immutable — a new upload always gets a new id.
     response.set('Cache-Control', 'private, max-age=31536000, immutable');
     const kind = inline ? 'inline' : 'attachment';
     return new StreamableFile(stream, {
       type: attachment.mimeType,
-      disposition: `${kind}; filename="${encodeURIComponent(attachment.fileName)}"`,
+      disposition: `${kind}; filename="${encodeURIComponent(downloadName)}"`,
     });
   }
 

apps/api/src/files/files.e2e.db.test.ts

@@ -327,6 +327,121 @@ describe.skipIf(!hasTestDb)('files (e2e, issue #27)', () => {
     expect(item.pageTitle).toBe(`Page Files ${suffix}`);
   });
 
+  it('prefixes downloads of classified attachments; unset pageId fails closed (issue #212)', async () => {
+    const page = await api()
+      .post(`/api/v1/ponds/${pondId}/pages`)
+      .set('Cookie', ownerCookie)
+      .send({ title: `Classified Files ${suffix}` })
+      .expect(201);
+
+    const uploaded = await api()
+      .post(`/api/v1/pages/${page.body.id}/files`)
+      .set('Cookie', ownerCookie)
+      .attach('file', Buffer.from('%PDF-1.4 classified content'), 'geheim.pdf')
+      .expect(201);
+
+    // Unclassified page: unchanged filename.
+    const openServed = await api()
+      .get(`/api/v1/media/${uploaded.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(openServed.headers['content-disposition']).toContain('filename="geheim.pdf"');
+
+    // Classified page: the documented VS-NfD_ prefix.
+    await prisma.page.update({
+      where: { id: page.body.id as string },
+      data: { classification: 'VS_NFD' },
+    });
+    const served = await api()
+      .get(`/api/v1/media/${uploaded.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(served.headers['content-disposition']).toContain('filename="VS-NfD_geheim.pdf"');
+
+    // pageId unset (paste-then-insert): fails closed to the pond's highest
+    // level — the pond now contains a classified page, so the orphan upload
+    // is served with the prefix too.
+    const orphan = await api()
+      .post(`/api/v1/ponds/${pondId}/files`)
+      .set('Cookie', ownerCookie)
+      .attach('file', Buffer.from('%PDF-1.4 orphan bytes'), 'lose-datei.pdf')
+      .expect(201);
+    const orphanServed = await api()
+      .get(`/api/v1/media/${orphan.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(orphanServed.headers['content-disposition']).toContain(
+      'filename="VS-NfD_lose-datei.pdf"',
+    );
+
+    // Back to all-open: the orphan serves unprefixed again.
+    await prisma.page.update({
+      where: { id: page.body.id as string },
+      data: { classification: 'UNCLASSIFIED' },
+    });
+    const openOrphan = await api()
+      .get(`/api/v1/media/${orphan.body.id}`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse(binaryParser as unknown as ParseCallback)
+      .expect(200);
+    expect(openOrphan.headers['content-disposition']).toContain('filename="lose-datei.pdf"');
+  });
+
+  it('blocks uploads to classified pages server-side when the policy says so (issue #213)', async () => {
+    const settings = app.get(InstanceSettingsService);
+    const page = await api()
+      .post(`/api/v1/ponds/${pondId}/pages`)
+      .set('Cookie', ownerCookie)
+      .send({ title: `Blocked Uploads ${suffix}` })
+      .expect(201);
+    await prisma.page.update({
+      where: { id: page.body.id as string },
+      data: { classification: 'VS_NFD' },
+    });
+
+    // Default policy `warn`: the upload is allowed (the UI shows the notice).
+    await api()
+      .post(`/api/v1/pages/${page.body.id}/files`)
+      .set('Cookie', ownerCookie)
+      .attach('file', Buffer.from('%PDF-1.4 warned upload'), 'warned.pdf')
+      .expect(201);
+
+    await settings.set('classification.uploadPolicy', 'block', 'test');
+    try {
+      // Enforced server-side, not only in the UI.
+      const blocked = await api()
+        .post(`/api/v1/pages/${page.body.id}/files`)
+        .set('Cookie', ownerCookie)
+        .attach('file', Buffer.from('%PDF-1.4 blocked upload'), 'blocked.pdf')
+        .expect(403);
+      expect((blocked.body as { code: string }).code).toBe('classified_upload_blocked');
+
+      // Unclassified pages stay uploadable under `block`.
+      const open = await api()
+        .post(`/api/v1/ponds/${pondId}/pages`)
+        .set('Cookie', ownerCookie)
+        .send({ title: `Open Uploads ${suffix}` })
+        .expect(201);
+      await api()
+        .post(`/api/v1/pages/${open.body.id}/files`)
+        .set('Cookie', ownerCookie)
+        .attach('file', Buffer.from('%PDF-1.4 open upload'), 'open.pdf')
+        .expect(201);
+    } finally {
+      await settings.set('classification.uploadPolicy', 'warn', 'test');
+      await prisma.instanceSetting.deleteMany({
+        where: { key: 'classification.uploadPolicy' },
+      });
+    }
+  });
+
   it('pond file manager reports usage, orphans, and page links (#61)', async () => {
     const page = await api()
       .post(`/api/v1/ponds/${pondId}/pages`)

apps/api/src/files/files.service.ts

@@ -3,6 +3,7 @@ import { Readable } from 'node:stream';
 
 import {
   BadRequestException,
+  ForbiddenException,
   Injectable,
   InternalServerErrorException,
   NotFoundException,
@@ -13,7 +14,9 @@ import {
   AttachmentListItemView,
   AttachmentView,
   PondFilesView,
+  PageClassification,
   SVG_MIME_TYPE,
+  classificationFilenamePrefix,
   fileExtension,
   isImageMimeType,
 } from '@dorfteich/shared';
@@ -36,6 +39,11 @@ export interface FileDownload {
    * else — office files, PDFs, and SVG — is always sent as a download so it
    * can never execute inline (ADR 0011, security.md §Uploads). */
   inline: boolean;
+  /** The filename for the Content-Disposition (issue #212, ADR 0022): the
+   * original name, prefixed `VS-NfD_` when the attachment's effective
+   * classification is vs_nfd — the one marker an arbitrary binary can
+   * carry. The file's CONTENT stays unmarked (documented residual risk). */
+  downloadName: string;
 }
 
 /** What the upload bytes resolved to after allowlist + SVG handling. */
@@ -198,6 +206,16 @@ export class FilesService {
   ): Promise<AttachmentView> {
     const page = await this.prisma.page.findFirst({ where: { id: pageId } });
     if (!page) throw new NotFoundException();
+    // Attaching to a classified page (issue #213, ADR 0022): the file will
+    // inherit a classification its content cannot carry (#212). The UI warns;
+    // the instance can harden the warning into a server-side block — enforced
+    // HERE, not only client-side.
+    if (page.classification === 'VS_NFD') {
+      const policy = await this.settings.get('classification.uploadPolicy');
+      if (policy === 'block') {
+        throw new ForbiddenException({ code: 'classified_upload_blocked' });
+      }
+    }
     return this.upload(user, page.pondId, file, page.id);
   }
 
@@ -229,13 +247,40 @@ export class FilesService {
         throw new InternalServerErrorException({ code: 'attachment_integrity_failure' });
       }
     }
+    const classification = await this.effectiveClassification(attachment);
     return {
       attachment,
       stream: Readable.from(buffer),
       inline: isImageMimeType(attachment.mimeType),
+      downloadName: `${classificationFilenamePrefix(classification)}${attachment.fileName}`,
     };
   }
 
+  /**
+   * The classification an attachment inherits (issue #212, ADR 0022): its
+   * page's level. An attachment whose `pageId` is still unset
+   * (paste-then-insert, pond-level files) FAILS CLOSED to the highest level
+   * of any live page in its pond — it could belong to any of them, so it is
+   * treated as classified as the most classified candidate. In an all-open
+   * pond that is `unclassified`, so nothing gets marked noise.
+   */
+  private async effectiveClassification(attachment: Attachment): Promise<PageClassification> {
+    if (attachment.pageId) {
+      const page = await this.prisma.page.findUnique({
+        where: { id: attachment.pageId },
+        select: { classification: true },
+      });
+      if (page) return page.classification.toLowerCase() as PageClassification;
+      // Page row gone but link set (race with purge): fall through to the
+      // pond-wide fail-closed answer below.
+    }
+    const classified = await this.prisma.page.findFirst({
+      where: { pondId: attachment.pondId, deletedAt: null, classification: 'VS_NFD' },
+      select: { id: true },
+    });
+    return classified ? 'vs_nfd' : 'unclassified';
+  }
+
   /**
    * Hash attachments that predate #199 (sha256 null), a bounded batch per
    * nightly run until none remain — idempotent by construction (hashed rows

apps/api/src/import-export/export.service.db.test.ts

@@ -263,6 +263,53 @@ describe.skipIf(!hasTestDb)('export (e2e, issue #65)', () => {
     expect(cache.markdown).not.toContain('classification:');
   });
 
+  it('adds a classification companion for classified media in the ZIP (issue #212)', async () => {
+    const image = await files.upload({ id: ownerId } as never, personalPondId, {
+      buffer: Buffer.from(PNG_BASE64, 'base64'),
+      size: 70,
+      originalname: 'secret-dot.png',
+    });
+    const slug = await seedPage(
+      personalPondId,
+      'Zip Media Classified',
+      `# Zip Media Classified\n\n![dot](${image.id})`,
+    );
+    await prisma.page.updateMany({
+      where: { pondId: personalPondId, slug },
+      data: { classification: 'VS_NFD' },
+    });
+
+    const res = await api()
+      .get(`/api/v1/ponds/${personalPondId}/export/markdown`)
+      .set('Cookie', ownerCookie)
+      .buffer(true)
+      .parse((r, cb) => {
+        const chunks: Buffer[] = [];
+        r.on('data', (c: Buffer) => chunks.push(c));
+        r.on('end', () => cb(null, Buffer.concat(chunks)));
+      })
+      .expect(200);
+    const entries = zipEntries(res.body as Buffer);
+
+    // Media inherits the highest referencing page's level: sibling companion
+    // carries the full marking; the manifest lists the media file's level.
+    const companion = entries[`media/${image.id}.png.classification.txt`];
+    expect(companion).toBeDefined();
+    expect(Buffer.from(companion!).toString('utf8')).toContain('VS – NUR FÜR DEN DIENSTGEBRAUCH');
+    const manifest = JSON.parse(Buffer.from(entries['manifest.json']!).toString('utf8')) as {
+      files: { path: string; classification: string }[];
+    };
+    expect(manifest.files).toContainEqual({
+      path: `media/${image.id}.png`,
+      classification: 'vs_nfd',
+    });
+
+    await prisma.page.updateMany({
+      where: { pondId: personalPondId, slug },
+      data: { classification: 'UNCLASSIFIED' },
+    });
+  });
+
   it('skips an attachment whose bytes are missing on disk instead of crashing', async () => {
     // An attachment row with no file (data drift): upload then remove the bytes.
     const image = await files.upload({ id: ownerId } as never, personalPondId, {

apps/api/src/import-export/export.service.ts

@@ -165,10 +165,20 @@ export class ExportService {
       manifestFiles.push({ path: `${prefix}${page.slug}.md`, classification: level });
     }
     for (const attachment of attachments) {
+      const mediaLevel = mediaClassification.get(attachment.id) ?? 'unclassified';
       manifestFiles.push({
         path: `${prefix}media/${mediaNameById.get(attachment.id)!}`,
-        classification: mediaClassification.get(attachment.id) ?? 'unclassified',
+        classification: mediaLevel,
       });
+      // Companion file for classified media (issue #212): the binary itself
+      // cannot carry the marking, so a sibling text file states it — it
+      // survives unpacking and copying, where the manifest may be dropped.
+      const mediaMarking = classificationMarking(mediaLevel);
+      if (mediaMarking) {
+        archive.append(`${mediaMarking}\n`, {
+          name: `${prefix}media/${mediaNameById.get(attachment.id)!}.classification.txt`,
+        });
+      }
     }
     // The archive-level manifest (#210): every file with its level, and the
     // highest level contained stated once — the bulk-egress channel stays

apps/api/src/public-api/openapi.ts

@@ -101,6 +101,13 @@ export function buildOpenApiDocument(): object {
           properties: {
             slug: { type: 'string' },
             title: { type: 'string' },
+            classification: {
+              type: 'string',
+              enum: ['unclassified', 'vs_nfd'],
+              description:
+                'VS-NfD marking level (ADR 0022). A marking, not access control; ' +
+                'consumers re-publishing content are expected to carry it onward.',
+            },
             parent: {
               type: ['string', 'null'],
               description:
@@ -118,6 +125,14 @@ export function buildOpenApiDocument(): object {
             slug: { type: 'string' },
             title: { type: 'string' },
             pondSlug: { type: 'string' },
+            classification: {
+              type: 'string',
+              enum: ['unclassified', 'vs_nfd'],
+              description:
+                'VS-NfD marking level (ADR 0022). A marking, not access control; ' +
+                'consumers re-publishing content are expected to carry it onward.',
+            },
+
             parent: {
               type: ['string', 'null'],
               description: 'Parent page slug; see PageListItem.parent.',

apps/api/src/public-api/public-api.e2e.db.test.ts

@@ -327,6 +327,35 @@ describe.skipIf(!hasTestDb)('public api v1 (e2e, issue #104)', () => {
       .expect(404);
   });
 
+  it('includes the classification in page representations (issue #211)', async () => {
+    const created = await pub()
+      .post(`/api/public/v1/ponds/${pondSlug}/pages`)
+      .set('Authorization', bearer('editor'))
+      .send({ title: `Classified Api Page ${suffix}`, markdown: 'classified body' })
+      .expect(201);
+    const slug = (created.body as { slug: string }).slug;
+    expect((created.body as { classification: string }).classification).toBe('unclassified');
+    await prisma.page.updateMany({
+      where: { slug, pond: { slug: pondSlug } },
+      data: { classification: 'VS_NFD' },
+    });
+
+    const fetched = await pub()
+      .get(`/api/public/v1/ponds/${pondSlug}/pages/${slug}`)
+      .set('Authorization', bearer('editor'))
+      .expect(200);
+    expect((fetched.body as { classification: string }).classification).toBe('vs_nfd');
+
+    const list = await pub()
+      .get(`/api/public/v1/ponds/${pondSlug}/pages`)
+      .set('Authorization', bearer('editor'))
+      .expect(200);
+    const listed = (list.body as { slug: string; classification: string }[]).find(
+      (p) => p.slug === slug,
+    );
+    expect(listed?.classification).toBe('vs_nfd');
+  });
+
   it('round-trips a page through Markdown, replaces content via the collab path', async () => {
     const markdown = '# Heading\n\nHello **world** from the API.\n';
     const created = await pub()

apps/api/src/public-api/public-api.service.ts

@@ -7,6 +7,7 @@ import {
   pondFeatureEnabled,
   pondSettingsSchema,
   type CommentListFilter,
+  type PageClassification,
   type PageListQuery,
   type CreateCommentInput,
   type CreateLabelInput,
@@ -110,6 +111,7 @@ export class PublicApiService {
     return items.map((item) => ({
       slug: item.slug,
       title: item.title,
+      classification: item.classification,
       parent: (item.parentId && slugById.get(item.parentId)) || null,
       labels: item.labelIds.map((id) => labelNames.get(id) ?? id).sort(),
       createdAt: item.createdAt,
@@ -129,6 +131,9 @@ export class PublicApiService {
       slug: page.slug,
       title: page.title,
       pondSlug,
+      // VS-NfD level (#211): part of the versioned representation so API
+      // consumers can carry the marking onward.
+      classification: page.classification.toLowerCase() as PageClassification,
       parent,
       markdown: cache?.markdown ?? '',
       html: cache?.html ?? '',

apps/api/src/public/feed.e2e.db.test.ts

@@ -145,6 +145,40 @@ describe.skipIf(!hasTestDb)('atom feeds (e2e, issue #149)', () => {
     expect(res.text).toContain(`/api/v1/public/${pondSlug}/newer-${suffix}`);
   });
 
+  it('marks classified entries and states the highest level at feed level (issue #211)', async () => {
+    // Unclassified feed: no category element at all (ADR 0022 — no noise).
+    const open = await api().get(`/api/v1/public/${pondSlug}/feed.xml`).expect(200);
+    expect(open.text).not.toContain('urn:dorfteich:classification');
+
+    await prisma.page.updateMany({
+      where: { pondId, slug: `newer-${suffix}` },
+      data: { classification: 'VS_NFD' },
+    });
+    try {
+      const res = await api().get(`/api/v1/public/${pondSlug}/feed.xml`).expect(200);
+      // The classified entry carries the documented category element…
+      expect(res.text).toContain(
+        '<category term="vs_nfd" scheme="urn:dorfteich:classification" ' +
+          'label="VS – NUR FÜR DEN DIENSTGEBRAUCH"/>',
+      );
+      // …and the feed document states the highest contained level once:
+      // 1 feed-level + 1 entry-level = exactly two categories (the open
+      // entry carries none).
+      expect(res.text.split('urn:dorfteich:classification').length - 1).toBe(2);
+
+      // The page feed of a classified page marks its entries and itself too.
+      const pageFeed = await api()
+        .get(`/api/v1/public/${pondSlug}/newer-${suffix}/feed.xml`)
+        .expect(200);
+      expect(pageFeed.text).toContain('urn:dorfteich:classification');
+    } finally {
+      await prisma.page.updateMany({
+        where: { pondId, slug: `newer-${suffix}` },
+        data: { classification: 'UNCLASSIFIED' },
+      });
+    }
+  });
+
   it('serves a page feed built from the version history', async () => {
     const res = await api().get(`/api/v1/public/${pondSlug}/newer-${suffix}/feed.xml`).expect(200);
     expect(res.text).toContain('<title>Newer Page — Feed Pond</title>');

apps/api/src/public/feed.service.ts

@@ -1,4 +1,9 @@
 import { Injectable, NotFoundException } from '@nestjs/common';
+import {
+  PageClassification,
+  classificationMarking,
+  highestClassification,
+} from '@dorfteich/shared';
 import { Pond, User } from '@prisma/client';
 
 import { PagesService } from '../pages/pages.service';
@@ -10,12 +15,18 @@ import { escapeHtml } from './html-shell';
 /** How many entries a feed carries — plenty for readers polling regularly. */
 const FEED_ENTRIES = 30;
 
+/** The documented scheme URI of the classification `<category>` element
+ * (issue #211, ADR 0022; see docs/self-hosting/public-api.md §Feeds). */
+const CLASSIFICATION_SCHEME = 'urn:dorfteich:classification';
+
 interface FeedEntry {
   id: string;
   title: string;
   link: string;
   updated: Date;
   summary?: string;
+  /** VS-NfD level (#211) — rendered as an Atom `<category>` when classified. */
+  classification?: PageClassification;
 }
 
 /**
@@ -60,6 +71,7 @@ export class FeedService {
           ? `${baseUrl}/api/v1/public/${pond.slug}/${page.slug}`
           : `${baseUrl}/p/${pond.slug}/${page.slug}`,
         updated: new Date(page.updatedAt),
+        classification: page.classification,
       }));
     return atomDocument({
       id: `${baseUrl}/api/v1/public/${pond.slug}/feed.xml`,
@@ -79,7 +91,7 @@ export class FeedService {
     const pond = await this.requireVisiblePond(user, pondSlug);
     const page = await this.prisma.page.findFirst({
       where: { pondId: pond.id, slug: pageSlug, deletedAt: null },
-      select: { id: true, pondId: true, slug: true, title: true },
+      select: { id: true, pondId: true, slug: true, title: true, classification: true },
     });
     if (!page || !(await this.permissions.canAccessPage(user, page, 'read'))) {
       throw new NotFoundException();
@@ -94,11 +106,13 @@ export class FeedService {
       user === null
         ? `${baseUrl}/api/v1/public/${pond.slug}/${page.slug}`
         : `${baseUrl}/p/${pond.slug}/${page.slug}`;
+    const pageLevel = page.classification.toLowerCase() as PageClassification;
     const entries = versions.map((version) => ({
       id: `urn:dorfteich:version:${version.id}`,
       title: version.label ?? version.trigger.toLowerCase(),
       link,
       updated: version.createdAt,
+      classification: pageLevel,
     }));
     return atomDocument({
       id: `${baseUrl}/api/v1/public/${pond.slug}/${page.slug}/feed.xml`,
@@ -118,6 +132,18 @@ export class FeedService {
   }
 }
 
+/** The classification as a standard Atom `<category>` (issue #211): `term` =
+ * the machine-readable level, `label` = the fixed marking wording. Only
+ * classified content carries one (ADR 0022: unclassified shows no marking). */
+function categoryTag(classification: PageClassification | undefined, indent: string): string {
+  const marking = classification ? classificationMarking(classification) : null;
+  if (!classification || !marking) return '';
+  return (
+    `${indent}<category term="${escapeHtml(classification)}" ` +
+    `scheme="${CLASSIFICATION_SCHEME}" label="${escapeHtml(marking)}"/>\n`
+  );
+}
+
 function atomDocument(feed: {
   id: string;
   title: string;
@@ -125,6 +151,10 @@ function atomDocument(feed: {
   entries: FeedEntry[];
 }): string {
   const updated = feed.entries[0]?.updated ?? new Date();
+  // The feed document states the highest level it contains (issue #211).
+  const highest = highestClassification(
+    feed.entries.map((entry) => entry.classification ?? 'unclassified'),
+  );
   const entries = feed.entries
     .map(
       (entry) =>
@@ -133,6 +163,7 @@ function atomDocument(feed: {
         `    <title>${escapeHtml(entry.title)}</title>\n` +
         `    <link href="${escapeHtml(entry.link)}"/>\n` +
         `    <updated>${entry.updated.toISOString()}</updated>\n` +
+        categoryTag(entry.classification, '    ') +
         (entry.summary ? `    <summary>${escapeHtml(entry.summary)}</summary>\n` : '') +
         `  </entry>`,
     )
@@ -143,6 +174,7 @@ function atomDocument(feed: {
     `  <id>${escapeHtml(feed.id)}</id>\n` +
     `  <title>${escapeHtml(feed.title)}</title>\n` +
     `  <link rel="self" href="${escapeHtml(feed.selfLink)}"/>\n` +
+    categoryTag(highest === 'unclassified' ? undefined : highest, '  ') +
     `  <updated>${updated.toISOString()}</updated>\n` +
     `${entries}\n` +
     `</feed>\n`

apps/api/src/public/html-shell.ts

@@ -42,6 +42,12 @@ export function htmlDocument({
     font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; line-height: 1.6; }
   img { max-width: 100%; height: auto; }
   .public-page__pond { color: #64748b; font-size: 0.9rem; }
+  /* VS-NfD marking (issue #211, ADR 0022): same convention as the SPA —
+     bold, centered, ruled band above and below the content. currentColor
+     keeps full contrast in both color schemes. */
+  .classification-banner { margin: 0.75rem 0; padding: 0.25rem 0.5rem;
+    border-top: 2px solid currentColor; border-bottom: 2px solid currentColor;
+    font-weight: 700; letter-spacing: 0.08em; text-align: center; font-size: 0.9rem; }
   pre { overflow-x: auto; }
   .public-footer { margin-top: 3rem; padding-top: 1rem; border-top: 1px solid #64748b;
     font-size: 0.9rem; }

apps/api/src/public/public.e2e.db.test.ts

@@ -109,6 +109,34 @@ describe.skipIf(!hasTestDb)('public read access (e2e, issue #56)', () => {
     expect((json.body as { html: string }).html).toContain('Hello world');
   });
 
+  it('renders the VS-NfD marking top and bottom in the no-JS shell (issue #211)', async () => {
+    const marking = 'VS – NUR FÜR DEN DIENSTGEBRAUCH';
+    // Unclassified: the shell carries no marking at all.
+    const open = await api().get(`/api/v1/public/${pondSlug}/${pageSlug}`).expect(200);
+    expect(open.text).not.toContain(marking);
+
+    await prisma.page.updateMany({
+      where: { pondId, slug: pageSlug },
+      data: { classification: 'VS_NFD' },
+    });
+    try {
+      const html = await api().get(`/api/v1/public/${pondSlug}/${pageSlug}`).expect(200);
+      // Above AND below the content — the shell is its own render path.
+      expect(html.text.split(`<p class="classification-banner">${marking}</p>`).length - 1).toBe(2);
+      const [before, after] = html.text.split('Hello world from a public page.');
+      expect(before).toContain(marking);
+      expect(after).toContain(marking);
+      // The JSON the SPA renders carries the level too (#206).
+      const json = await api().get(`/api/v1/public/${pondSlug}/${pageSlug}/content`).expect(200);
+      expect((json.body as { classification: string }).classification).toBe('vs_nfd');
+    } finally {
+      await prisma.page.updateMany({
+        where: { pondId, slug: pageSlug },
+        data: { classification: 'UNCLASSIFIED' },
+      });
+    }
+  });
+
   it('never resolves a non-public page for an anonymous visitor', async () => {
     await api().get(`/api/v1/public/${privatePondSlug}/${privatePageSlug}`).expect(404);
     await api().get(`/api/v1/public/${privatePondSlug}/${privatePageSlug}/content`).expect(404);

apps/api/src/public/public.service.ts

@@ -1,4 +1,5 @@
 import { Injectable, NotFoundException } from '@nestjs/common';
+import { classificationMarking } from '@dorfteich/shared';
 import type { PageClassification, PageCommentsView } from '@dorfteich/shared';
 import { Page, Pond, User } from '@prisma/client';
 
@@ -194,6 +195,12 @@ export class PublicService {
     canonical: string,
   ): Promise<string> {
     const content = await this.content(user, pondSlug, pageSlug);
+    // The VS-NfD marking renders in the same places as the SPA — above and
+    // below the content (issue #211, ADR 0022). The no-JS shell is its own
+    // render path, so it carries its own banner markup; unclassified pages
+    // get none.
+    const marking = classificationMarking(content.classification);
+    const banner = marking ? `<p class="classification-banner">${escapeHtml(marking)}</p>\n` : '';
     // No session-dependent content: this document is identical for every viewer
     // who may read the page (crawler-safe, cacheable). The shared shell adds
     // the legal footer links (issue #82) in the instance default locale.
@@ -206,9 +213,10 @@ export class PublicService {
         `/api/v1/public/${encodeURIComponent(pondSlug)}/feed.xml`,
         canonical,
       ).toString(),
-      bodyHtml: `<p class="public-page__pond">${escapeHtml(content.pondName)}</p>
+      bodyHtml: `${banner}<p class="public-page__pond">${escapeHtml(content.pondName)}</p>
 <h1>${escapeHtml(content.title)}</h1>
-${content.html}`,
+${content.html}
+${banner}`,
     });
   }
 }

apps/api/src/search/postgres-search.provider.ts

@@ -1,5 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import {
+  PageClassification,
   SEARCH_HIGHLIGHT_END,
   SEARCH_HIGHLIGHT_START,
   SEARCH_RESULT_LIMIT,
@@ -34,6 +35,7 @@ interface SearchRow {
   pondName: string;
   labelIds: string[];
   snippet: string;
+  classification: string;
 }
 
 /**
@@ -159,6 +161,7 @@ export class PostgresSearchProvider extends SearchProvider {
 
     const rows = await this.prisma.$queryRaw<SearchRow[]>(Prisma.sql`
       SELECT p.id AS "pageId", p.title, p.slug, p.pond_id AS "pondId",
+             p.classification::text AS classification,
              po.slug AS "pondSlug", po.name AS "pondName",
              COALESCE(
                ARRAY(SELECT pl.label_id FROM page_labels pl WHERE pl.page_id = p.id),
@@ -210,6 +213,8 @@ export class PostgresSearchProvider extends SearchProvider {
         pondName: row.pondName,
         labelIds: row.labelIds,
         snippet: row.snippet,
+        // A hit on a classified page is never shown unmarked (#211).
+        classification: row.classification.toLowerCase() as PageClassification,
       }));
   }
 }

apps/api/src/search/search.provider.test.ts

@@ -23,6 +23,7 @@ describe('SearchProvider DI seam (issue #49)', () => {
       pondSlug: 'pond',
       pondName: 'Pond',
       labelIds: [],
+      classification: 'unclassified',
       snippet: 'a snippet',
     };
     const fake: SearchProvider = {

apps/api/src/search/search.service.db.test.ts

@@ -90,6 +90,20 @@ describe.skipIf(!hasTestDb)('PostgresSearchProvider (db, issue #49)', () => {
     expect(results[0]!.pageId).toBe(titleHit);
   });
 
+  it('carries the classification with every hit — a classified snippet is never unmarked (issue #211)', async () => {
+    const classifiedId = await makePage(`classified ${term} note`, `secret ${term} content`);
+    await prisma.page.update({
+      where: { id: classifiedId },
+      data: { classification: 'VS_NFD' },
+    });
+    const results = await search.search({ q: term }, owner);
+    const classified = results.find((r) => r.pageId === classifiedId);
+    expect(classified?.classification).toBe('vs_nfd');
+    // Every other hit carries the field too, as `unclassified`.
+    const other = results.find((r) => r.pageId !== classifiedId);
+    expect(other?.classification).toBe('unclassified');
+  });
+
   it('highlights the match in the snippet', async () => {
     const results = await search.search({ q: term }, owner);
     const bodyHit = results.find((r) => r.snippet.includes(SEARCH_HIGHLIGHT_START));

apps/api/src/settings/instance-settings.service.ts

@@ -57,6 +57,11 @@ export const INSTANCE_SETTINGS = {
   // parent page (#205) wins over this default. The marking is not a
   // protection mechanism — permissions ignore it.
   'classification.newPageDefault': z.enum(['unclassified', 'vs_nfd']).default('unclassified'),
+  // Attaching files to a classified page (issue #213, ADR 0022): the UI
+  // always warns (the file inherits a classification its content cannot
+  // carry, #212); `block` hardens the warning into a server-side rejection.
+  // Default `warn` — blocking is the reference-configuration choice (#227).
+  'classification.uploadPolicy': z.enum(['warn', 'block']).default('warn'),
   // Non-image upload allowlist (ADR 0011, issue #61): lowercase extensions
   // without the dot. Images are always allowed regardless; SVG is governed
   // by `upload.svgPolicy`. Normalized (lowercased, dot-stripped, deduped) so

apps/web/e2e/attachments.spec.ts

@@ -109,3 +109,19 @@ test('pond file manager shows usage and flags an orphan (Pond Admin)', async ({
 
   await context.close();
 });
+
+test('shows the classified-upload warning on a classified page (issue #213)', async ({
+  browser,
+}) => {
+  const context = await contextForUser(browser, BASE_URL, 'fixture-user');
+  const page = await context.newPage();
+  await page.goto('/p/content-fixtures/classified-note');
+  await openAttachments(page);
+  // The persistent warning names the consequence; the wording is the fixed
+  // marking formula (ADR 0022), not localized.
+  await expect(page.locator('.attachments-panel__warning')).toBeVisible();
+  await expect(page.locator('.attachments-panel__warning')).toContainText(
+    'VS – NUR FÜR DEN DIENSTGEBRAUCH',
+  );
+  await context.close();
+});

apps/web/src/files/AttachmentsPanel.tsx

@@ -1,4 +1,4 @@
-import type { AttachmentListItemView } from '@dorfteich/shared';
+import type { AttachmentListItemView, PageClassification } from '@dorfteich/shared';
 import { useQuery, useQueryClient } from '@tanstack/react-query';
 import type { Editor } from '@tiptap/react';
 import { useRef, useState } from 'react';
@@ -19,11 +19,16 @@ export function AttachmentsPanel({
   pageId,
   editor,
   canEdit,
+  classification,
   onClose,
 }: {
   pageId: string;
   editor: Editor | null;
   canEdit: boolean;
+  /** VS-NfD level of the page (issue #213): a classified page shows the
+   * upload warning naming the consequence — attachments inherit a level
+   * their content cannot carry (#212). */
+  classification?: PageClassification;
   onClose: () => void;
 }): React.JSX.Element {
   const { t } = useTranslation('files');
@@ -96,6 +101,12 @@ export function AttachmentsPanel({
 
       <FormError error={error} />
 
+      {canEdit && classification === 'vs_nfd' && (
+        <p className="attachments-panel__warning" role="note">
+          {t('classifiedUploadWarning')}
+        </p>
+      )}
+
       {canEdit && (
         <div className="attachments-panel__upload">
           <input

apps/web/src/pages/AdminSettingsPage.tsx

@@ -29,6 +29,7 @@ interface InstanceSettings {
   'upload.allowedExtensions': string[];
   'upload.svgPolicy': 'reject' | 'sanitize';
   'classification.newPageDefault': 'unclassified' | 'vs_nfd';
+  'classification.uploadPolicy': 'warn' | 'block';
   'legal.imprint': string;
   'legal.privacyPolicy': string;
   'home.content': string;
@@ -101,6 +102,15 @@ export function AdminSettingsPage(): React.JSX.Element {
                 <option value="vs_nfd">{t('settings:admin.classificationVsNfd')}</option>
               </select>
             </Field>
+            <Field
+              label={t('settings:admin.uploadPolicy')}
+              hint={t('settings:admin.uploadPolicyHelp')}
+            >
+              <select {...form.register('classification.uploadPolicy')}>
+                <option value="warn">{t('settings:admin.uploadPolicyWarn')}</option>
+                <option value="block">{t('settings:admin.uploadPolicyBlock')}</option>
+              </select>
+            </Field>
             <button type="submit" className="button" disabled={form.formState.isSubmitting}>
               {t('settings:admin.save')}
             </button>

apps/web/src/pages/PageEditorPage.tsx

@@ -1,5 +1,10 @@
 import { DEFAULT_FONTS, extractOutline } from '@dorfteich/shared';
-import type { PageListItemView, PageStateView, PondView } from '@dorfteich/shared';
+import type {
+  PageClassification,
+  PageListItemView,
+  PageStateView,
+  PondView,
+} from '@dorfteich/shared';
 import { useQuery, useQueryClient } from '@tanstack/react-query';
 import { Collaboration } from '@tiptap/extension-collaboration';
 import { EditorContent, useEditor } from '@tiptap/react';
@@ -126,6 +131,8 @@ interface ResolvedPage {
   pondId: string;
   slug: string;
   title: string;
+  /** VS-NfD level (issue #213); undefined for the offline-cache fallback. */
+  classification?: PageClassification;
 }
 
 function PageEditor({
@@ -305,6 +312,7 @@ function PageEditor({
               pageId={page.id}
               editor={editor}
               canEdit={canEdit}
+              classification={page.classification}
               onClose={onCloseAttachments}
             />
           )}
@@ -421,7 +429,13 @@ export function PageEditorPage(): React.JSX.Element {
   const offlineCached = !navigator.onLine && !page.data ? recallPage(pondSlug, pageSlug) : null;
 
   const resolved: ResolvedPage | null = page.data
-    ? { id: page.data.id, pondId: page.data.pondId, slug: page.data.slug, title: page.data.title }
+    ? {
+        id: page.data.id,
+        pondId: page.data.pondId,
+        slug: page.data.slug,
+        title: page.data.title,
+        classification: page.data.classification,
+      }
     : offlineCached
       ? {
           id: offlineCached.pageId,

apps/web/src/search/SearchPalette.tsx

@@ -1,3 +1,4 @@
+import { classificationMarking } from '@dorfteich/shared';
 import type { PondView, SearchResultView } from '@dorfteich/shared';
 import { useQuery } from '@tanstack/react-query';
 import { useEffect, useMemo, useRef, useState } from 'react';
@@ -43,6 +44,7 @@ function saveRecent(query: string): string[] {
  */
 export function SearchPalette({ onClose }: { onClose: () => void }): React.JSX.Element {
   const { t } = useTranslation('search');
+  const { t: tCommon } = useTranslation('common');
   const navigate = useNavigate();
   const { pondSlug } = useCurrentPondRoute();
   const inputRef = useRef<HTMLInputElement>(null);
@@ -220,6 +222,14 @@ export function SearchPalette({ onClose }: { onClose: () => void }): React.JSX.E
                   onClick={() => open(hit)}
                 >
                   <span className="search-result__title">{hit.title}</span>
+                  {/* A hit on a classified page is never shown unmarked
+                      (issue #211, ADR 0022) — fixed wording, not localized. */}
+                  {classificationMarking(hit.classification) && (
+                    <span className="search-result__classification">
+                      <span className="visually-hidden">{tCommon('classification.label')}: </span>
+                      {classificationMarking(hit.classification)}
+                    </span>
+                  )}
                   <span className="search-result__pond">{t('inPond', { pond: hit.pondName })}</span>
                   <LabelChips labelIds={hit.labelIds} byId={byId} />
                   <span className="search-result__snippet">

apps/web/src/styles/base.css

@@ -2809,6 +2809,16 @@ ul[data-type='task_list'] li p:last-of-type {
   font-size: 0.85rem;
 }
 
+/* VS-NfD marking on a search hit (issue #211, ADR 0022): compact form of the
+   banner — text token only, full contrast in both themes. */
+.search-result__classification {
+  display: block;
+  color: var(--color-text);
+  font-size: 0.75rem;
+  font-weight: 700;
+  letter-spacing: 0.08em;
+}
+
 .search-result__snippet {
   display: block;
   margin-top: 2px;
@@ -3061,6 +3071,17 @@ ul[data-type='task_list'] li p:last-of-type {
   margin: 0;
 }
 
+/* Upload warning on classified pages (issue #213, ADR 0022) — a persistent
+   note, not a dismissable toast: the consequence applies to every upload. */
+.attachments-panel__warning {
+  margin: 0 0 var(--space-2);
+  padding: var(--space-2);
+  border: 1px solid var(--color-border);
+  border-left: 3px solid currentColor;
+  font-size: 0.85rem;
+  color: var(--color-text);
+}
+
 .attachments-panel__upload {
   display: flex;
   align-items: center;

docs/architecture/adr/0022-page-classification.md

@@ -62,7 +62,10 @@ guardrails). Separation is a platform property.
    labels _around_ it (e.g. an accessibility label naming the element) are
    i18n'd. The single source is `classificationMarking()` in
    `@dorfteich/shared` (`packages/shared/src/pages.ts`); no output channel
-   hard-codes the string.
+   hard-codes the string. Where a full wording cannot live — file NAMES of
+   attachment downloads (#212) — the established short form `VS-NfD` is
+   used as the prefix `VS-NfD_`, single source
+   `classificationFilenamePrefix()` in the same module.
 
 ## Consequences
 

docs/architecture/operations.md

@@ -192,3 +192,25 @@ not a copy of the purged page.
 | max upload size                 | 25 MiB (quota ladder, ADR 0011)                  |
 | collab connections per instance | 500 concurrent                                   |
 | rate limits                     | login 10/min/IP, signup 5/h/IP, API 100/min/user |
+
+## Classified attachment downloads (issue #212, ADR 0022)
+
+An attachment is an opaque binary — the application cannot write the
+VS-NfD marking into arbitrary file formats. The marking therefore lives
+**around** the file:
+
+- **Filename prefix `VS-NfD_`** on every download whose effective
+  classification is `vs_nfd` (single source:
+  `classificationFilenamePrefix()` in `@dorfteich/shared`).
+- **Effective classification**: the linked page's level. An attachment
+  whose `pageId` is not (yet) set — paste-then-insert, pond-level files —
+  **fails closed** to the highest level of any live page in its pond.
+- **Containing archive**: the pond export ZIP states each media file's
+  level in `manifest.json` and adds a sibling
+  `<file>.classification.txt` companion carrying the full marking for
+  classified media.
+
+Residual risk, deliberately documented rather than hidden (recorded on
+issue #231): the file's own **content** carries no marking — a user who
+renames the file has an unmarked classified binary. Marking file contents
+would require rewriting arbitrary formats, which ADR 0019 rules out.

docs/self-hosting/public-api.md

@@ -52,6 +52,28 @@ curl -H "Authorization: Bearer dt_pat_..." \
 Deliberately not in v1 (stage 2): attachment upload, version endpoints,
 webhooks.
 
+### Classification (VS-NfD marking, issue #211 / ADR 0022)
+
+Every page representation (`GET …/pages`, `GET …/pages/{pageSlug}`)
+carries a `classification` field: `"unclassified"` or `"vs_nfd"`. It is a
+**marking, not access control** — permissions are unchanged by it. API
+consumers that render or re-publish page content are expected to carry
+the marking onward (the fixed wording is
+`VS – NUR FÜR DEN DIENSTGEBRAUCH`).
+
+The Atom feeds mark classified content with a standard `<category>`
+element on both levels:
+
+```xml
+<category term="vs_nfd" scheme="urn:dorfteich:classification"
+          label="VS – NUR FÜR DEN DIENSTGEBRAUCH"/>
+```
+
+Each classified entry carries one, and the feed document itself carries
+one stating the **highest** level it contains. Unclassified entries and
+all-open feeds carry none (marking everything trains readers to ignore
+markings, ADR 0022).
+
 ## Connect Claude Code / MCP clients
 
 The instance ships its own MCP endpoint (Streamable HTTP) at `/api/mcp` —

docs/vs-nfd/20-massnahmenplan.md

@@ -57,9 +57,9 @@ _Meilenstein: `M26 — VS-NfD: classification metadata`_
   - [x] PDF via gotenberg (`pdf-html.ts` Header/Footer-Template) · 1 AT · #208
   - [x] DOCX/ODT via pandoc (Reference-Doc mit Kopf-/Fußzeile) · 2–3 AT · #209
   - [x] Markdown-ZIP (Frontmatter + Aufdruck) · 1 AT · #210
-  - [ ] Atom-Feeds, Public-API, Suchergebnisse, No-JS-Shell · 2–3 AT · #211
+  - [x] Atom-Feeds, Public-API, Suchergebnisse, No-JS-Shell · 2–3 AT · #211
-  - [ ] Attachment-Download (Dateiname-Präfix + Begleitdatei) · 1–2 AT · #212
+  - [x] Attachment-Download (Dateiname-Präfix + Begleitdatei) · 1–2 AT · #212
-- [ ] Warnung/Sperre beim Anhängen an eingestufte Seiten · 1 AT · #213
+- [x] Warnung/Sperre beim Anhängen an eingestufte Seiten · 1 AT · #213
 
 ### P1-3 Verifizierter Offline-/Airgap-Pfad · 8–10 AT ⟵ neu aus Roadmap
 

packages/shared/i18n/de/errors.json

@@ -110,5 +110,6 @@
   "backup_set_not_found": "Das gewählte Backup-Set wurde nicht gefunden.",
   "scope_required": "Dieses API-Token hat nicht den erforderlichen Scope.",
   "pond_not_found": "Der Teich existiert nicht.",
-  "classification_lower_forbidden": "Zum Herabstufen der Einstufung fehlt die Berechtigung (Teich-Admin erforderlich)."
+  "classification_lower_forbidden": "Zum Herabstufen der Einstufung fehlt die Berechtigung (Teich-Admin erforderlich).",
+  "classified_upload_blocked": "Uploads auf eingestufte Seiten sind auf dieser Instanz blockiert."
 }

packages/shared/i18n/de/files.json

@@ -19,5 +19,6 @@
     "svgSanitize": "Bereinigen (Skripte entfernen)",
     "svgReject": "Ablehnen",
     "save": "Upload-Einstellungen speichern"
-  }
+  },
+  "classifiedUploadWarning": "Diese Seite ist als „VS – NUR FÜR DEN DIENSTGEBRAUCH\" eingestuft. Angehängte Dateien erben die Einstufung; die Datei selbst trägt im Inhalt keine Kennzeichnung (nur Dateinamens-Präfix und Begleitdatei beim Download)."
 }

packages/shared/i18n/de/settings.json

@@ -52,7 +52,11 @@
     "newPageClassification": "Einstufung neuer Seiten",
     "newPageClassificationHelp": "Standard-Einstufung (VS-NfD-Kennzeichnung) für neu angelegte Seiten. Die Kennzeichnung ist keine Zugriffskontrolle; die Trennung von Einstufungsniveaus leistet die Umgebung (eine Instanz je Niveau).",
     "classificationUnclassified": "Offen — keine Kennzeichnung",
-    "classificationVsNfd": "VS – NUR FÜR DEN DIENSTGEBRAUCH"
+    "classificationVsNfd": "VS – NUR FÜR DEN DIENSTGEBRAUCH",
+    "uploadPolicy": "Datei-Uploads auf eingestufte Seiten",
+    "uploadPolicyHelp": "Anhänge erben die Einstufung der Seite, tragen selbst aber keine Kennzeichnung im Inhalt. „Blockieren\" lehnt Uploads auf eingestufte Seiten serverseitig ab.",
+    "uploadPolicyWarn": "Warnen — Upload mit deutlichem Hinweis erlauben",
+    "uploadPolicyBlock": "Blockieren — Uploads auf eingestufte Seiten ablehnen"
   },
   "landing": {
     "title": "Startseite",

packages/shared/i18n/en/errors.json

@@ -110,5 +110,6 @@
   "backup_set_not_found": "The selected backup set was not found.",
   "scope_required": "This API token does not have the required scope.",
   "pond_not_found": "The pond does not exist.",
-  "classification_lower_forbidden": "You lack the permission to lower the classification (Pond Admin required)."
+  "classification_lower_forbidden": "You lack the permission to lower the classification (Pond Admin required).",
+  "classified_upload_blocked": "Uploads to classified pages are blocked on this instance."
 }

packages/shared/i18n/en/files.json

@@ -19,5 +19,6 @@
     "svgSanitize": "Sanitize (strip scripts)",
     "svgReject": "Reject",
     "save": "Save upload settings"
-  }
+  },
+  "classifiedUploadWarning": "This page is classified “VS – NUR FÜR DEN DIENSTGEBRAUCH”. Attached files inherit the classification; the file content itself carries no marking (only the filename prefix and companion file on download)."
 }

packages/shared/i18n/en/settings.json

@@ -52,7 +52,11 @@
     "newPageClassification": "Classification of new pages",
     "newPageClassificationHelp": "Default classification (VS-NfD marking) for newly created pages. The marking is not access control; separating classification levels is the environment’s job (one instance per level).",
     "classificationUnclassified": "Open — no marking",
-    "classificationVsNfd": "VS – NUR FÜR DEN DIENSTGEBRAUCH"
+    "classificationVsNfd": "VS – NUR FÜR DEN DIENSTGEBRAUCH",
+    "uploadPolicy": "File uploads to classified pages",
+    "uploadPolicyHelp": "Attachments inherit the page’s classification but carry no marking in their content. “Block” rejects uploads to classified pages server-side.",
+    "uploadPolicyWarn": "Warn — allow the upload with a clear notice",
+    "uploadPolicyBlock": "Block — reject uploads to classified pages"
   },
   "landing": {
     "title": "Landing page",

packages/shared/src/pages.ts

@@ -26,6 +26,16 @@ export function classificationMarking(classification: PageClassification): strin
   return classification === 'vs_nfd' ? 'VS – NUR FÜR DEN DIENSTGEBRAUCH' : null;
 }
 
+/**
+ * File-name-safe short marker for downloads (issue #212, ADR 0022): an
+ * arbitrary binary cannot carry the marking inside, so its NAME does. The
+ * established short form of the German marking is `VS-NfD`; the full
+ * wording stays the on-screen/companion form. Empty for unclassified.
+ */
+export function classificationFilenamePrefix(classification: PageClassification): string {
+  return classification === 'vs_nfd' ? 'VS-NfD_' : '';
+}
+
 /** Ordering of levels: the index in {@link PAGE_CLASSIFICATIONS} (lowest
  * first) — the tree invariant (#205) and archive-level statements (#210)
  * compare through this, never through string comparison. */

packages/shared/src/public-api.ts

@@ -3,6 +3,7 @@ import { z } from 'zod';
 import type { ApiTokenScope } from './api-tokens';
 import type { CommentView } from './comments';
 import type { LabelTreeNode, LabelView } from './labels';
+import type { PageClassification } from './pages';
 
 /**
  * Wire types of the public REST API (`/api/public/v1`, issue #104). The
@@ -29,6 +30,8 @@ export interface PublicPondView {
 export interface PublicPageListItemView {
   slug: string;
   title: string;
+  /** VS-NfD level (issue #211, ADR 0022) — see `docs/self-hosting/public-api.md`. */
+  classification: PageClassification;
   /** Parent page slug in the tree (issue #110), or null at the root — nulled
    * as well when the token's user may not read the parent (no existence leak). */
   parent: string | null;
@@ -41,6 +44,8 @@ export interface PublicPageView {
   slug: string;
   title: string;
   pondSlug: string;
+  /** VS-NfD level (issue #211, ADR 0022) — see `docs/self-hosting/public-api.md`. */
+  classification: PageClassification;
   /** Parent page slug (issue #110); see {@link PublicPageListItemView.parent}. */
   parent: string | null;
   markdown: string;

packages/shared/src/search.ts

@@ -1,5 +1,7 @@
 import { z } from 'zod';
 
+import type { PageClassification } from './pages';
+
 /**
  * Search schemas and views (issue #49/#50, ADR 0010). Full-text search runs on
  * PostgreSQL behind the `SearchProvider` interface. Diacritic-insensitive
@@ -49,4 +51,7 @@ export interface SearchResultView {
   labelIds: string[];
   /** Snippet with matches wrapped in the highlight sentinels above. */
   snippet: string;
+  /** VS-NfD level (issue #211, ADR 0022): a snippet of a classified page is
+   * never shown unmarked — the UI renders the marking with every hit. */
+  classification: PageClassification;
 }