diff --git a/admin-compliance/app/api/sdk/v1/master-controls/route.ts b/admin-compliance/app/api/sdk/v1/master-controls/route.ts
index 4dd70f5f..009e14a9 100644
--- a/admin-compliance/app/api/sdk/v1/master-controls/route.ts
+++ b/admin-compliance/app/api/sdk/v1/master-controls/route.ts
@@ -10,6 +10,19 @@ const dbUrl = process.env.COMPLIANCE_DATABASE_URL ||
 
 const pool = new Pool({ connectionString: dbUrl })
 
+// handleMeta returns global (filter-independent) counts incl. a ~2s member-join
+// facet. It is refetched on every filter change, so cache it briefly.
+let metaCache: { at: number; data: unknown } | null = null
+const META_TTL_MS = 120_000
+
+type MCListRow = {
+  id: string; control_id: string; title: string; objective: string
+  severity: string; category: string; total_controls: number
+  phases_covered: string[] | null; created_at: string
+  verification_method: string | null; use_cases: string[] | null
+  primary_regulation: string | null
+}
+
 /**
  * MC API that returns data in the same format as the canonical controls
  * endpoint. This allows the MC page to reuse ControlListView components.
@@ -43,17 +56,14 @@ export async function GET(request: NextRequest) {
   }
 }
 
-async function handleControls(params: URLSearchParams) {
-  const search = params.get('search') || ''
-  const limit = Math.min(parseInt(params.get('limit') || '50'), 200)
-  const offset = parseInt(params.get('offset') || '0')
-  const sort = params.get('sort') || 'control_id'
-  const order = params.get('order') === 'desc' ? 'DESC' : 'ASC'
-
+// Shared WHERE builder so list + count stay in lock-step (incl. the
+// use_case / verification_method / source_regulation mapping filters).
+function buildControlsWhere(params: URLSearchParams): { where: string; args: unknown[]; idx: number } {
   let where = "WHERE 1=1"
   const args: unknown[] = []
   let idx = 1
 
+  const search = params.get('search') || ''
   if (search) {
     where += ` AND mc.canonical_name ILIKE $${idx}`
     args.push(`%${search}%`)
@@ -61,11 +71,9 @@ async function handleControls(params: URLSearchParams) {
   }
 
   const severity = params.get('severity') || ''
-  if (severity) {
-    if (severity === 'high') { where += ` AND mc.total_controls > 100` }
-    else if (severity === 'medium') { where += ` AND mc.total_controls BETWEEN 20 AND 100` }
-    else if (severity === 'low') { where += ` AND mc.total_controls < 20` }
-  }
+  if (severity === 'high') { where += ` AND mc.total_controls > 100` }
+  else if (severity === 'medium') { where += ` AND mc.total_controls BETWEEN 20 AND 100` }
+  else if (severity === 'low') { where += ` AND mc.total_controls < 20` }
 
   const domain = params.get('domain') || ''
   if (domain) {
@@ -74,6 +82,67 @@ async function handleControls(params: URLSearchParams) {
     idx++
   }
 
+  const useCase = params.get('use_case') || ''
+  const primaryOnly = params.get('primary') === '1'
+  if (useCase) {
+    where += ` AND EXISTS (SELECT 1 FROM compliance.mc_use_case_mappings m
+                 WHERE m.master_control_uuid = mc.id AND m.use_case = $${idx}${primaryOnly ? ' AND m.is_primary' : ''})`
+    args.push(useCase)
+    idx++
+  }
+
+  const verification = params.get('verification_method') || ''
+  if (verification === '__none__') {
+    where += ` AND NOT EXISTS (SELECT 1 FROM compliance.mc_verification v
+                 WHERE v.master_control_uuid = mc.id)`
+  } else if (verification) {
+    where += ` AND EXISTS (SELECT 1 FROM compliance.mc_verification v
+                 WHERE v.master_control_uuid = mc.id AND v.verification_method = $${idx})`
+    args.push(verification)
+    idx++
+  }
+
+  const regulation = params.get('source_regulation') || ''
+  if (regulation) {
+    where += ` AND EXISTS (SELECT 1 FROM compliance.mc_regulations r
+                 WHERE r.master_control_uuid = mc.id AND r.source_regulation = $${idx})`
+    args.push(regulation)
+    idx++
+  }
+
+  const mapped = params.get('mapped') || ''
+  if (mapped === 'mapped') {
+    where += ` AND EXISTS (SELECT 1 FROM compliance.mc_use_case_mappings m
+                 WHERE m.master_control_uuid = mc.id)`
+  } else if (mapped === 'unmapped') {
+    where += ` AND NOT EXISTS (SELECT 1 FROM compliance.mc_use_case_mappings m
+                 WHERE m.master_control_uuid = mc.id)`
+  }
+
+  // Member-based filter: an MC matches if ANY of its atomic members has the
+  // category. Only category/severity/release_state are populated on the
+  // deduplicated members; evidence_type, target_audience and source_citation
+  // are 100% NULL there, so those canonical filters cannot apply to MCs
+  // without an upstream backfill (wiring them would just return 0).
+  const category = params.get('category') || ''
+  if (category) {
+    where += ` AND EXISTS (SELECT 1 FROM compliance.master_control_members mcm
+                 JOIN compliance.canonical_controls cc ON cc.id = mcm.control_uuid
+                 WHERE mcm.master_control_uuid = mc.id AND cc.category = $${idx})`
+    args.push(category); idx++
+  }
+
+  return { where, args, idx }
+}
+
+async function handleControls(params: URLSearchParams) {
+  const limit = Math.min(parseInt(params.get('limit') || '50'), 200)
+  const offset = parseInt(params.get('offset') || '0')
+  const sort = params.get('sort') || 'control_id'
+  const order = params.get('order') === 'desc' ? 'DESC' : 'ASC'
+
+  const { where, args, idx } = buildControlsWhere(params)
+
   const sortCol = sort === 'control_id' ? 'mc.master_control_id' :
                   sort === 'created_at' ? 'mc.created_at' :
                   sort === 'source' ? 'mc.canonical_name' : 'mc.master_control_id'
@@ -90,7 +159,14 @@ async function handleControls(params: URLSearchParams) {
            mc.total_controls,
            mc.phases_covered,
            mc.id,
-           mc.created_at
+           mc.created_at,
+           (SELECT v.verification_method FROM compliance.mc_verification v
+             WHERE v.master_control_uuid = mc.id) as verification_method,
+           (SELECT array_agg(m.use_case ORDER BY m.is_primary DESC, m.use_case)
+              FROM compliance.mc_use_case_mappings m
+             WHERE m.master_control_uuid = mc.id) as use_cases,
+           (SELECT r.source_regulation FROM compliance.mc_regulations r
+             WHERE r.master_control_uuid = mc.id AND r.is_primary LIMIT 1) as primary_regulation
     FROM compliance.master_controls mc
     ${where}
     ORDER BY ${sortCol} ${order}
@@ -98,7 +174,7 @@ async function handleControls(params: URLSearchParams) {
   `, args)
 
   // Map to canonical control format
-  const controls = res.rows.map(r => ({
+  const controls = res.rows.map((r: MCListRow) => ({
     id: r.id,
     control_id: r.control_id,
     title: r.title,
@@ -106,10 +182,11 @@ async function handleControls(params: URLSearchParams) {
     severity: r.severity,
     category: r.category,
     release_state: 'active',
-    source_citation: null,
-    verification_method: null,
+    source_citation: r.primary_regulation ? { source: r.primary_regulation } : null,
+    verification_method: r.verification_method,
     evidence_type: null,
     target_audience: [],
+    use_cases: r.use_cases || [],
     requirements: [],
     test_procedure: [],
     evidence: [],
@@ -126,22 +203,17 @@ async function handleControls(params: URLSearchParams) {
 }
 
 async function handleCount(params: URLSearchParams) {
-  const search = params.get('search') || ''
-  let where = "WHERE 1=1"
-  const args: unknown[] = []
-
-  if (search) {
-    where += ` AND mc.canonical_name ILIKE $1`
-    args.push(`%${search}%`)
-  }
-
+  const { where, args } = buildControlsWhere(params)
   const res = await pool.query(
     `SELECT count(*) FROM compliance.master_controls mc ${where}`, args
   )
   return NextResponse.json({ total: parseInt(res.rows[0].count) })
 }
 
-async function handleMeta(params: URLSearchParams) {
+async function handleMeta(_params: URLSearchParams) {
+  if (metaCache && Date.now() - metaCache.at < META_TTL_MS) {
+    return NextResponse.json(metaCache.data)
+  }
   const res = await pool.query(`
     SELECT count(*) as total,
            count(CASE WHEN total_controls > 100 THEN 1 END) as high_count,
@@ -158,21 +230,59 @@ async function handleMeta(params: URLSearchParams) {
     GROUP BY 1 ORDER BY 2 DESC LIMIT 30
   `)
 
-  return NextResponse.json({
-    total: parseInt(r.total),
+  // Mapping distribution + coverage + member-derived category facet. Only
+  // category is populated on the deduplicated members (evidence_type /
+  // target_audience are NULL there), so it is the one canonical facet we surface.
+  const [ucRes, vRes, regRes, mappedRes, catRes] = await Promise.all([
+    pool.query(`SELECT use_case, count(DISTINCT master_control_uuid) c
+                FROM compliance.mc_use_case_mappings GROUP BY 1 ORDER BY 2 DESC`),
+    pool.query(`SELECT verification_method, count(*) c
+                FROM compliance.mc_verification GROUP BY 1 ORDER BY 2 DESC`),
+    pool.query(`SELECT source_regulation, count(DISTINCT master_control_uuid) c
+                FROM compliance.mc_regulations GROUP BY 1 ORDER BY 2 DESC LIMIT 200`),
+    pool.query(`SELECT count(DISTINCT master_control_uuid) c
+                FROM compliance.mc_use_case_mappings`),
+    pool.query(`SELECT cc.category v, count(DISTINCT mcm.master_control_uuid) c
+                FROM compliance.master_control_members mcm
+                JOIN compliance.canonical_controls cc ON cc.id = mcm.control_uuid
+                WHERE cc.category IS NOT NULL GROUP BY 1 ORDER BY 2 DESC`),
+  ])
+  const facet = (rows: Array<{ v: string; c: string }>) =>
+    Object.fromEntries(rows.filter(x => x.v).map(x => [x.v, parseInt(x.c)]))
+
+  const total = parseInt(r.total)
+  const mappedTotal = parseInt(mappedRes.rows[0].c)
+
+  const payload = {
+    total,
     severity_counts: {
       high: parseInt(r.high_count),
       medium: parseInt(r.medium_count),
       low: parseInt(r.low_count),
     },
-    domains: domainRes.rows.map(d => ({ domain: d.domain, count: parseInt(d.count) })),
+    domains: domainRes.rows.map((d: { domain: string; count: string }) =>
+      ({ domain: d.domain, count: parseInt(d.count) })),
     sources: [],
     no_source_count: 0,
-    release_state_counts: { active: parseInt(r.total) },
-    verification_method_counts: {},
-    category_counts: {},
+    release_state_counts: { active: total },
+    verification_method_counts: Object.fromEntries(
+      vRes.rows.map((x: { verification_method: string; c: string }) =>
+        [x.verification_method, parseInt(x.c)])),
+    category_counts: facet(catRes.rows),
     evidence_type_counts: {},
-  })
+    use_case_counts: Object.fromEntries(
+      ucRes.rows
+        .filter((x: { use_case: string | null }) => x.use_case)
+        .map((x: { use_case: string; c: string }) => [x.use_case, parseInt(x.c)])),
+    regulations: regRes.rows
+      .filter((x: { source_regulation: string | null }) => x.source_regulation)
+      .map((x: { source_regulation: string; c: string }) =>
+        ({ source_regulation: x.source_regulation, count: parseInt(x.c) })),
+    mapped_total: mappedTotal,
+    unmapped_count: total - mappedTotal,
+  }
+  metaCache = { at: Date.now(), data: payload }
+  return NextResponse.json(payload)
 }
 
 async function handleDetail(params: URLSearchParams) {
@@ -201,6 +311,23 @@ async function handleDetail(params: URLSearchParams) {
     LIMIT 100
   `, [mc.id])
 
+  // Use-case / verification / regulation mapping (the "regulation→code" lineage)
+  const mapRes = await pool.query(`
+    SELECT
+      (SELECT json_agg(json_build_object('use_case', m.use_case, 'is_primary', m.is_primary)
+                ORDER BY m.is_primary DESC, m.use_case)
+         FROM compliance.mc_use_case_mappings m WHERE m.master_control_uuid = $1) as use_cases,
+      (SELECT v.verification_method FROM compliance.mc_verification v
+         WHERE v.master_control_uuid = $1) as verification_method,
+      (SELECT json_agg(json_build_object('source_regulation', r.source_regulation,
+                'is_primary', r.is_primary, 'member_count', r.member_count)
+                ORDER BY r.is_primary DESC, r.member_count DESC)
+         FROM compliance.mc_regulations r WHERE r.master_control_uuid = $1) as regulations
+  `, [mc.id])
+  const mapping = mapRes.rows[0] || {}
+  const regs = mapping.regulations || []
+  const primaryReg = regs.find((x: { is_primary: boolean }) => x.is_primary) || regs[0]
+
   return NextResponse.json({
     id: mc.id,
     control_id: mc.control_id,
@@ -220,7 +347,10 @@ async function handleDetail(params: URLSearchParams) {
     evidence: [],
     open_anchors: [],
     target_audience: [],
-    source_citation: null,
+    verification_method: mapping.verification_method || null,
+    use_cases: mapping.use_cases || [],
+    regulations: regs,
+    source_citation: primaryReg ? { source: primaryReg.source_regulation } : null,
     scope: { platforms: [], components: [], data_classes: [] },
     risk_score: null,
     implementation_effort: null,
diff --git a/admin-compliance/app/sdk/control-library/__tests__/mcMappingLabels.test.ts b/admin-compliance/app/sdk/control-library/__tests__/mcMappingLabels.test.ts
new file mode 100644
index 00000000..6d29274a
--- /dev/null
+++ b/admin-compliance/app/sdk/control-library/__tests__/mcMappingLabels.test.ts
@@ -0,0 +1,44 @@
+import { describe, it, expect } from 'vitest'
+import {
+  USE_CASE_LABELS, MC_VERIFICATION_LABELS, useCaseLabel, mcVerificationLabel,
+} from '../components/mcMappingLabels'
+
+describe('useCaseLabel', () => {
+  it('maps known use-case keys to German labels', () => {
+    expect(useCaseLabel('impressum')).toBe('Impressum')
+    expect(useCaseLabel('cookie_banner')).toBe('Cookie-Banner')
+    expect(useCaseLabel('code_security')).toBe('Code Security')
+    expect(useCaseLabel('dse')).toBe('Datenschutzerklärung')
+  })
+
+  it('humanizes an unknown key instead of showing the raw slug', () => {
+    expect(useCaseLabel('brand_new_thing')).toBe('Brand New Thing')
+  })
+})
+
+describe('mcVerificationLabel', () => {
+  it('maps the master-control verification methods', () => {
+    expect(mcVerificationLabel('source_code')).toBe('Source Code')
+    expect(mcVerificationLabel('it_process')).toBe('IT-Prozess')
+    expect(mcVerificationLabel('network')).toBe('Netzwerk/Infra')
+    expect(mcVerificationLabel('document')).toBe('Dokument')
+  })
+
+  it('humanizes an unknown method', () => {
+    expect(mcVerificationLabel('telepathy')).toBe('Telepathy')
+  })
+})
+
+describe('label coverage', () => {
+  it('labels the security/code use cases (>=50% code+process focus)', () => {
+    for (const k of ['code_security', 'network_security', 'cra', 'isms', 'tisax']) {
+      expect(USE_CASE_LABELS[k]).toBeTruthy()
+    }
+  })
+
+  it('covers every master-control verification method', () => {
+    for (const m of ['document', 'source_code', 'network', 'it_process', 'hybrid', 'manual']) {
+      expect(MC_VERIFICATION_LABELS[m]).toBeTruthy()
+    }
+  })
+})
diff --git a/admin-compliance/app/sdk/control-library/components/ControlListView.tsx b/admin-compliance/app/sdk/control-library/components/ControlListView.tsx
index 719ecb96..90dce7b7 100644
--- a/admin-compliance/app/sdk/control-library/components/ControlListView.tsx
+++ b/admin-compliance/app/sdk/control-library/components/ControlListView.tsx
@@ -12,6 +12,7 @@ import {
   VERIFICATION_METHODS, CATEGORY_OPTIONS, EVIDENCE_TYPE_OPTIONS,
 } from './helpers'
 import { ControlsMeta } from './useControlLibraryState'
+import { useCaseLabel, mcVerificationLabel } from './mcMappingLabels'
 import { GeneratorModal } from './GeneratorModal'
 
 interface ControlListViewProps {
@@ -34,6 +35,10 @@ interface ControlListViewProps {
   domainFilter: string
   stateFilter: string
   verificationFilter: string
+  useCaseFilter: string
+  primaryOnly: boolean
+  regulationFilter: string
+  mappedFilter: string
   categoryFilter: string
   evidenceTypeFilter: string
   audienceFilter: string
@@ -46,6 +51,10 @@ interface ControlListViewProps {
   setDomainFilter: (v: string) => void
   setStateFilter: (v: string) => void
   setVerificationFilter: (v: string) => void
+  setUseCaseFilter: (v: string) => void
+  setPrimaryOnly: (v: boolean) => void
+  setRegulationFilter: (v: string) => void
+  setMappedFilter: (v: string) => void
   setCategoryFilter: (v: string) => void
   setEvidenceTypeFilter: (v: string) => void
   setAudienceFilter: (v: string) => void
@@ -71,10 +80,12 @@ export function ControlListView({
   reviewCount, bulkProcessing, showStats, processedStats,
   showGenerator, currentPage, totalPages, sortBy,
   searchQuery, severityFilter, domainFilter, stateFilter,
-  verificationFilter, categoryFilter, evidenceTypeFilter, audienceFilter,
+  verificationFilter, useCaseFilter, primaryOnly, regulationFilter, mappedFilter,
+  categoryFilter, evidenceTypeFilter, audienceFilter,
   sourceFilter, typeFilter, hideDuplicates,
   setSearchQuery, setSeverityFilter, setDomainFilter, setStateFilter,
-  setVerificationFilter, setCategoryFilter, setEvidenceTypeFilter, setAudienceFilter,
+  setVerificationFilter, setUseCaseFilter, setPrimaryOnly, setRegulationFilter, setMappedFilter,
+  setCategoryFilter, setEvidenceTypeFilter, setAudienceFilter,
   setSourceFilter, setTypeFilter, setHideDuplicates, setSortBy,
   setShowStats, setShowGenerator, setCurrentPage,
   onSelectControl, onCreateMode, onEnterReview, onBulkReject, onRefresh, onLoadStats, onFullReload,
@@ -176,18 +187,60 @@ export function ControlListView({
                 className="rounded border-gray-300 text-purple-600 focus:ring-purple-500" />
               Duplikate ausblenden
             </label>
+            {meta?.use_case_counts && (
+              <select value={useCaseFilter} onChange={e => setUseCaseFilter(e.target.value)}
+                className="text-sm border border-purple-300 bg-purple-50 rounded-lg px-2 py-1.5 focus:outline-none focus:ring-2 focus:ring-purple-500 max-w-[260px]">
+                <option value="">Use Case (alle)</option>
+                {Object.entries(meta.use_case_counts).sort((a, b) => b[1] - a[1]).map(([k, c]) => (
+                  <option key={k} value={k}>{useCaseLabel(k)} ({c})</option>
+                ))}
+              </select>
+            )}
+            {meta?.use_case_counts && useCaseFilter && (
+              <label className="flex items-center gap-1.5 text-xs text-gray-600 cursor-pointer whitespace-nowrap"
+                title="Nur Master Controls, deren Primärzweck dieser Use Case ist (blendet über-geclusterte Mehrfachzwecke aus)">
+                <input type="checkbox" checked={primaryOnly} onChange={e => setPrimaryOnly(e.target.checked)}
+                  className="rounded border-gray-300 text-purple-600 focus:ring-purple-500" />
+                nur Primärzweck
+              </label>
+            )}
+            {meta?.regulations && meta.regulations.length > 0 && (
+              <select value={regulationFilter} onChange={e => setRegulationFilter(e.target.value)}
+                className="text-sm border border-blue-300 bg-blue-50 rounded-lg px-2 py-1.5 focus:outline-none focus:ring-2 focus:ring-purple-500 max-w-[260px]">
+                <option value="">Regulierung (alle)</option>
+                {meta.regulations.map(rg => (
+                  <option key={rg.source_regulation} value={rg.source_regulation}>{rg.source_regulation} ({rg.count})</option>
+                ))}
+              </select>
+            )}
             <select value={verificationFilter} onChange={e => setVerificationFilter(e.target.value)}
               className="text-sm border border-gray-300 rounded-lg px-2 py-1.5 focus:outline-none focus:ring-2 focus:ring-purple-500">
               <option value="">Nachweis</option>
               {Object.entries(VERIFICATION_METHODS).map(([k, v]) => (
                 <option key={k} value={k}>{v.label}{meta?.verification_method_counts?.[k] ? ` (${meta.verification_method_counts[k]})` : ''}</option>
               ))}
+              {Object.keys(meta?.verification_method_counts || {})
+                .filter(k => k !== '__none__' && !(k in VERIFICATION_METHODS))
+                .map(k => (
+                  <option key={k} value={k}>{mcVerificationLabel(k)} ({meta!.verification_method_counts![k]})</option>
+                ))}
               {meta?.verification_method_counts?.['__none__'] ? <option value="__none__">Ohne Nachweis ({meta.verification_method_counts['__none__']})</option> : null}
             </select>
+            {meta?.mapped_total != null && (
+              <select value={mappedFilter} onChange={e => setMappedFilter(e.target.value)}
+                className="text-sm border border-gray-300 rounded-lg px-2 py-1.5 focus:outline-none focus:ring-2 focus:ring-purple-500">
+                <option value="">Coverage: alle</option>
+                <option value="mapped">Zugeordnet ({meta.mapped_total})</option>
+                <option value="unmapped">Offen ({meta.unmapped_count ?? 0})</option>
+              </select>
+            )}
             <select value={categoryFilter} onChange={e => setCategoryFilter(e.target.value)}
               className="text-sm border border-gray-300 rounded-lg px-2 py-1.5 focus:outline-none focus:ring-2 focus:ring-purple-500">
               <option value="">Kategorie</option>
               {CATEGORY_OPTIONS.map(c => <option key={c.value} value={c.value}>{c.label}{meta?.category_counts?.[c.value] ? ` (${meta.category_counts[c.value]})` : ''}</option>)}
+              {Object.keys(meta?.category_counts || {})
+                .filter(k => k !== '__none__' && !CATEGORY_OPTIONS.some(c => c.value === k))
+                .map(k => <option key={k} value={k}>{k} ({meta!.category_counts![k]})</option>)}
               {meta?.category_counts?.['__none__'] ? <option value="__none__">Ohne Kategorie ({meta.category_counts['__none__']})</option> : null}
             </select>
             <select value={evidenceTypeFilter} onChange={e => setEvidenceTypeFilter(e.target.value)}
diff --git a/admin-compliance/app/sdk/control-library/components/mcMappingLabels.ts b/admin-compliance/app/sdk/control-library/components/mcMappingLabels.ts
new file mode 100644
index 00000000..ac19346e
--- /dev/null
+++ b/admin-compliance/app/sdk/control-library/components/mcMappingLabels.ts
@@ -0,0 +1,65 @@
+// Display labels for the master-control mapping dimensions (use case +
+// verification method). Keys mirror the backend use_case_registry; an unknown
+// key humanizes gracefully so a newly-seeded use case still renders.
+
+export const USE_CASE_LABELS: Record<string, string> = {
+  impressum: 'Impressum',
+  telekommunikation: 'Telekommunikation (TKG)',
+  dse: 'Datenschutzerklärung',
+  agb: 'AGB',
+  cookie_banner: 'Cookie-Banner',
+  widerruf: 'Widerruf',
+  dsr: 'Betroffenenrechte (DSR)',
+  loeschkonzept: 'Löschkonzept',
+  avv: 'Auftragsverarbeitung (AVV)',
+  dsfa: 'DSFA',
+  code_security: 'Code Security',
+  network_security: 'Network Security',
+  cra: 'Cyber Resilience Act',
+  isms: 'ISMS',
+  tisax: 'TISAX',
+  kritis: 'KRITIS',
+  dora: 'DORA',
+  ai_act: 'AI Act',
+  mica: 'MiCA',
+  mdr: 'Medizinprodukte (MDR)',
+  maschinen: 'Maschinenverordnung',
+  batterie: 'Batterieverordnung',
+  ehds: 'EHDS',
+  produktsicherheit: 'Produktsicherheit',
+  dsa: 'Digital Services Act',
+  dma: 'Digital Markets Act',
+  data_governance: 'Data Governance Act',
+  zahlungsdienste: 'Zahlungsdienste (PSD2)',
+  geldwaesche: 'Geldwäsche (GwG)',
+  lieferkette: 'Lieferkettengesetz',
+  whistleblowing: 'Whistleblowing',
+  barrierefreiheit: 'Barrierefreiheit (BFSG)',
+  verbraucherschutz: 'Verbraucherschutz',
+  urheberrecht: 'Urheberrecht',
+  wettbewerbsrecht: 'Wettbewerbsrecht',
+  gleichbehandlung: 'Gleichbehandlung (AGG)',
+  steuerrecht: 'Steuerrecht',
+  handelsrecht: 'Handelsrecht',
+}
+
+export const MC_VERIFICATION_LABELS: Record<string, string> = {
+  document: 'Dokument',
+  source_code: 'Source Code',
+  network: 'Netzwerk/Infra',
+  it_process: 'IT-Prozess',
+  hybrid: 'Hybrid',
+  manual: 'Manuell',
+}
+
+function humanize(key: string): string {
+  return key.replace(/_/g, ' ').replace(/\b\w/g, c => c.toUpperCase())
+}
+
+export function useCaseLabel(key: string): string {
+  return USE_CASE_LABELS[key] || humanize(key)
+}
+
+export function mcVerificationLabel(key: string): string {
+  return MC_VERIFICATION_LABELS[key] || humanize(key)
+}
diff --git a/admin-compliance/app/sdk/control-library/components/useControlLibraryState.ts b/admin-compliance/app/sdk/control-library/components/useControlLibraryState.ts
index 8a123e31..b770a0d0 100644
--- a/admin-compliance/app/sdk/control-library/components/useControlLibraryState.ts
+++ b/admin-compliance/app/sdk/control-library/components/useControlLibraryState.ts
@@ -14,6 +14,11 @@ export interface ControlsMeta {
   category_counts?: Record<string, number>
   evidence_type_counts?: Record<string, number>
   release_state_counts?: Record<string, number>
+  // Master-control mapping dimensions (only returned by the MC endpoint)
+  use_case_counts?: Record<string, number>
+  regulations?: Array<{ source_regulation: string; count: number }>
+  mapped_total?: number
+  unmapped_count?: number
 }
 
 const PAGE_SIZE = 50
@@ -35,6 +40,10 @@ export function useControlLibraryState(backendUrlOverride?: string) {
   const [domainFilter, setDomainFilter] = useState<string>('')
   const [stateFilter, setStateFilter] = useState<string>('')
   const [verificationFilter, setVerificationFilter] = useState<string>('')
+  const [useCaseFilter, setUseCaseFilter] = useState<string>('')
+  const [primaryOnly, setPrimaryOnly] = useState<boolean>(false)
+  const [regulationFilter, setRegulationFilter] = useState<string>('')
+  const [mappedFilter, setMappedFilter] = useState<string>('')
   const [categoryFilter, setCategoryFilter] = useState<string>('')
   const [evidenceTypeFilter, setEvidenceTypeFilter] = useState<string>('')
   const [audienceFilter, setAudienceFilter] = useState<string>('')
@@ -88,6 +97,10 @@ export function useControlLibraryState(backendUrlOverride?: string) {
     if (domainFilter) p.set('domain', domainFilter)
     if (stateFilter) p.set('release_state', stateFilter)
     if (verificationFilter) p.set('verification_method', verificationFilter)
+    if (useCaseFilter) p.set('use_case', useCaseFilter)
+    if (primaryOnly) p.set('primary', '1')
+    if (regulationFilter) p.set('source_regulation', regulationFilter)
+    if (mappedFilter) p.set('mapped', mappedFilter)
     if (categoryFilter) p.set('category', categoryFilter)
     if (evidenceTypeFilter) p.set('evidence_type', evidenceTypeFilter)
     if (audienceFilter) p.set('target_audience', audienceFilter)
@@ -97,7 +110,7 @@ export function useControlLibraryState(backendUrlOverride?: string) {
     if (debouncedSearch) p.set('search', debouncedSearch)
     if (extra) for (const [k, v] of Object.entries(extra)) p.set(k, v)
     return p.toString()
-  }, [severityFilter, domainFilter, stateFilter, verificationFilter, categoryFilter, evidenceTypeFilter, audienceFilter, sourceFilter, typeFilter, hideDuplicates, debouncedSearch])
+  }, [severityFilter, domainFilter, stateFilter, verificationFilter, useCaseFilter, primaryOnly, regulationFilter, mappedFilter, categoryFilter, evidenceTypeFilter, audienceFilter, sourceFilter, typeFilter, hideDuplicates, debouncedSearch])
 
   const loadFrameworks = useCallback(async () => {
     try {
@@ -156,7 +169,7 @@ export function useControlLibraryState(backendUrlOverride?: string) {
   useEffect(() => { loadFrameworks(); loadReviewCount() }, [loadFrameworks, loadReviewCount])
   useEffect(() => { loadMeta() }, [loadMeta])
   useEffect(() => { loadControls() }, [loadControls])
-  useEffect(() => { setCurrentPage(1) }, [severityFilter, domainFilter, stateFilter, verificationFilter, categoryFilter, evidenceTypeFilter, audienceFilter, sourceFilter, typeFilter, hideDuplicates, debouncedSearch, sortBy])
+  useEffect(() => { setCurrentPage(1) }, [severityFilter, domainFilter, stateFilter, verificationFilter, useCaseFilter, primaryOnly, regulationFilter, mappedFilter, categoryFilter, evidenceTypeFilter, audienceFilter, sourceFilter, typeFilter, hideDuplicates, debouncedSearch, sortBy])
 
   const totalPages = Math.max(1, Math.ceil(totalCount / PAGE_SIZE))
 
@@ -212,6 +225,10 @@ export function useControlLibraryState(backendUrlOverride?: string) {
     domainFilter, setDomainFilter,
     stateFilter, setStateFilter,
     verificationFilter, setVerificationFilter,
+    useCaseFilter, setUseCaseFilter,
+    primaryOnly, setPrimaryOnly,
+    regulationFilter, setRegulationFilter,
+    mappedFilter, setMappedFilter,
     categoryFilter, setCategoryFilter,
     evidenceTypeFilter, setEvidenceTypeFilter,
     audienceFilter, setAudienceFilter,
diff --git a/admin-compliance/app/sdk/control-library/page.tsx b/admin-compliance/app/sdk/control-library/page.tsx
index cdc7bd4c..c3bb2948 100644
--- a/admin-compliance/app/sdk/control-library/page.tsx
+++ b/admin-compliance/app/sdk/control-library/page.tsx
@@ -232,6 +232,10 @@ export default function ControlLibraryPage() {
       domainFilter={state.domainFilter}
       stateFilter={state.stateFilter}
       verificationFilter={state.verificationFilter}
+      useCaseFilter={state.useCaseFilter}
+      primaryOnly={state.primaryOnly}
+      regulationFilter={state.regulationFilter}
+      mappedFilter={state.mappedFilter}
       categoryFilter={state.categoryFilter}
       evidenceTypeFilter={state.evidenceTypeFilter}
       audienceFilter={state.audienceFilter}
@@ -243,6 +247,10 @@ export default function ControlLibraryPage() {
       setDomainFilter={state.setDomainFilter}
       setStateFilter={state.setStateFilter}
       setVerificationFilter={state.setVerificationFilter}
+      setUseCaseFilter={state.setUseCaseFilter}
+      setPrimaryOnly={state.setPrimaryOnly}
+      setRegulationFilter={state.setRegulationFilter}
+      setMappedFilter={state.setMappedFilter}
       setCategoryFilter={state.setCategoryFilter}
       setEvidenceTypeFilter={state.setEvidenceTypeFilter}
       setAudienceFilter={state.setAudienceFilter}
diff --git a/admin-compliance/app/sdk/master-controls/page.tsx b/admin-compliance/app/sdk/master-controls/page.tsx
index 7b24aaf2..ca4f04cb 100644
--- a/admin-compliance/app/sdk/master-controls/page.tsx
+++ b/admin-compliance/app/sdk/master-controls/page.tsx
@@ -3,6 +3,7 @@
 import React, { useState, useEffect } from 'react'
 import { ControlListView } from '../control-library/components/ControlListView'
 import { useControlLibraryState } from '../control-library/components/useControlLibraryState'
+import { useCaseLabel, mcVerificationLabel } from '../control-library/components/mcMappingLabels'
 
 /**
  * Master Controls page — reuses the Control Library UI exactly,
@@ -38,7 +39,7 @@ export default function MasterControlsPage() {
   if (state.mode === 'detail' && state.selectedControl) {
     return (
       <MCDetail
-        mc={state.selectedControl}
+        mc={state.selectedControl as unknown as Record<string, unknown>}
         onBack={() => { state.setMode('list'); state.setSelectedControl(null) }}
       />
     )
@@ -65,6 +66,10 @@ export default function MasterControlsPage() {
       domainFilter={state.domainFilter}
       stateFilter={state.stateFilter}
       verificationFilter={state.verificationFilter}
+      useCaseFilter={state.useCaseFilter}
+      primaryOnly={state.primaryOnly}
+      regulationFilter={state.regulationFilter}
+      mappedFilter={state.mappedFilter}
       categoryFilter={state.categoryFilter}
       evidenceTypeFilter={state.evidenceTypeFilter}
       audienceFilter={state.audienceFilter}
@@ -76,6 +81,10 @@ export default function MasterControlsPage() {
       setDomainFilter={state.setDomainFilter}
       setStateFilter={state.setStateFilter}
       setVerificationFilter={state.setVerificationFilter}
+      setUseCaseFilter={state.setUseCaseFilter}
+      setPrimaryOnly={state.setPrimaryOnly}
+      setRegulationFilter={state.setRegulationFilter}
+      setMappedFilter={state.setMappedFilter}
       setCategoryFilter={state.setCategoryFilter}
       setEvidenceTypeFilter={state.setEvidenceTypeFilter}
       setAudienceFilter={state.setAudienceFilter}
@@ -116,8 +125,15 @@ const SEV = {
   low: 'bg-blue-100 text-blue-800',
 } as Record<string, string>
 
+interface MCMapping {
+  use_cases?: Array<{ use_case: string; is_primary: boolean }>
+  verification_method?: string | null
+  regulations?: Array<{ source_regulation: string; is_primary: boolean; member_count: number }>
+}
+
 function MCDetail({ mc, onBack }: { mc: Record<string, unknown>; onBack: () => void }) {
   const [members, setMembers] = useState<Member[]>([])
+  const [mapping, setMapping] = useState<MCMapping>({})
   const [loading, setLoading] = useState(true)
   const [phaseFilter, setPhaseFilter] = useState('')
 
@@ -131,6 +147,10 @@ function MCDetail({ mc, onBack }: { mc: Record<string, unknown>; onBack: () => v
     fetch(`/api/sdk/v1/master-controls?endpoint=control&id=${mcId}`)
       .then(r => r.ok ? r.json() : null)
       .then(data => {
+        if (data) setMapping({
+          use_cases: data.use_cases, verification_method: data.verification_method,
+          regulations: data.regulations,
+        })
         if (data?.members) setMembers(data.members)
         else if (data?.requirements) {
           // Fallback: parse requirements strings
@@ -164,6 +184,33 @@ function MCDetail({ mc, onBack }: { mc: Record<string, unknown>; onBack: () => v
         <h1 className="text-2xl font-bold text-gray-900">{mcName}</h1>
         <p className="text-gray-500 mt-1">{mcId} — {totalControls} Atomic Controls</p>
 
+        {/* Zuordnung: Use Cases + Verifikation + Quell-Regulierung */}
+        {(mapping.use_cases?.length || mapping.verification_method || mapping.regulations?.length) ? (
+          <div className="mt-4 flex flex-wrap items-center gap-2">
+            {(mapping.use_cases || []).map(u => (
+              <span key={u.use_case}
+                className={`px-2 py-0.5 rounded text-xs font-medium ${u.is_primary
+                  ? 'bg-purple-100 text-purple-800 border border-purple-300'
+                  : 'bg-purple-50 text-purple-600'}`}
+                title={u.is_primary ? 'Primärzweck' : 'Mehrfachzweck'}>
+                {useCaseLabel(u.use_case)}{u.is_primary ? ' ★' : ''}
+              </span>
+            ))}
+            {mapping.verification_method && (
+              <span className="px-2 py-0.5 rounded text-xs font-medium bg-emerald-100 text-emerald-800 border border-emerald-300">
+                Nachweis: {mcVerificationLabel(mapping.verification_method)}
+              </span>
+            )}
+            {(mapping.regulations || []).slice(0, 4).map(r => (
+              <span key={r.source_regulation}
+                className="px-2 py-0.5 rounded text-xs bg-blue-50 text-blue-700"
+                title={`${r.member_count} Member${r.is_primary ? ' · Primärquelle' : ''}`}>
+                {r.source_regulation}{r.is_primary ? ' ★' : ''}
+              </span>
+            ))}
+          </div>
+        ) : null}
+
         {/* Phase badges */}
         <div className="flex flex-wrap gap-2 mt-4">
           {uniquePhases.map(p => (
diff --git a/backend-compliance/compliance/data/use_case_registry.py b/backend-compliance/compliance/data/use_case_registry.py
index 46bdb0dd..80bdffc5 100644
--- a/backend-compliance/compliance/data/use_case_registry.py
+++ b/backend-compliance/compliance/data/use_case_registry.py
@@ -55,6 +55,11 @@ _USE_CASES: tuple[UseCase, ...] = (
             doc_types=("impressum",), scope_tokens=("impressum",),
             categories=("compliance",),
             keyword_tokens=("impressum", "anbieterkennzeichnung")),
+    UseCase("telekommunikation", "Telekommunikation (TKG)", "product",
+            regulations=("TKG",),
+            verification_methods=("document", "it_process"),
+            categories=("compliance", "governance"),
+            keyword_tokens=("telekommunikation", "tkg")),
     UseCase("dse", "Datenschutzerklärung", "document",
             regulations=("DSGVO",),
             verification_methods=("document",),
@@ -270,12 +275,18 @@ _REGULATION_RULES: tuple[tuple[str, str], ...] = (
     # Website / Telemedien / Recht (User-Domaene)
     ("tdddg", "cookie_banner"),
     ("eprivacy", "cookie_banner"),
-    ("telemedien", "impressum"),
-    ("telekommunikationsgesetz", "impressum"),
-    ("tkg", "impressum"),
+    # Telemediengesetz (das echte Impressumsrecht) VOR der "telemedien"-
+    # Leitlinien-Regel — longest-first, sonst faengt "telemedien" es ab.
+    ("telemediengesetz", "impressum"),
+    # "DSK OH Telemedien" ist eine Datenschutz-Leitlinie, kein Impressumsrecht.
+    ("telemedien", "dse"),
+    # TKG / AT-TKG sind Telekommunikationsrecht, NICHT Website-Impressum.
+    ("telekommunikationsgesetz", "telekommunikation"),
+    ("tkg", "telekommunikation"),
     ("tmg", "impressum"),
     ("mediengesetz", "impressum"),
-    ("gewerbeordnung", "impressum"),
+    # Gewerbeordnung ist Gewerbe-/Handelsrecht, kein Impressum.
+    ("gewerbeordnung", "handelsrecht"),
     ("e-commerce", "agb"),
     ("digitale-inhalte", "agb"),
     ("konsumentenschutz", "verbraucherschutz"),
diff --git a/backend-compliance/scripts/classify_mc_use_cases.py b/backend-compliance/scripts/classify_mc_use_cases.py
index 2ee85690..66a74531 100644
--- a/backend-compliance/scripts/classify_mc_use_cases.py
+++ b/backend-compliance/scripts/classify_mc_use_cases.py
@@ -125,7 +125,7 @@ async def run_seed(conn, limit: int = 0) -> dict:
     await conn.execute(
         """INSERT INTO compliance.mc_use_case_sync_state
            (registry_hash, stage, total_mappings, mcs_classified)
-           VALUES ($1,'seed_source_regulation',$2,$3)""",
+           VALUES ($1,'seed_regulation',$2,$3)""",
         reg.registry_hash(), total, n_mc)
     return {"mcs_mapped": n_mc, "regulation_rows": n_reg,
             "use_case_rows": n_uc, "verification_rows": n_v}
diff --git a/backend-compliance/tests/test_use_case_registry.py b/backend-compliance/tests/test_use_case_registry.py
index 09c05fe4..6d4f5e7c 100644
--- a/backend-compliance/tests/test_use_case_registry.py
+++ b/backend-compliance/tests/test_use_case_registry.py
@@ -122,7 +122,8 @@ def test_regulation_mapper_known():
         "Cyber Resilience Act (CRA)": "cra",
         "DSGVO (EU) 2016/679": "dse",
         "EDPB Facial Recognition": "dse",      # Leitlinie → Datenschutz
-        "TKG": "impressum",
+        "TKG": "telekommunikation",            # Telekom-Recht, NICHT Impressum
+        "TMG": "impressum",                    # echtes Impressumsrecht
         "TDDDG": "cookie_banner",
         "Markets in Crypto-Assets (MiCA)": "mica",
         "BGB": "agb",
@@ -131,6 +132,19 @@ def test_regulation_mapper_known():
         assert reg.use_case_for_regulation(reg_str) == expected, reg_str
 
 
+def test_regulation_mapper_impressum_misroutes_fixed():
+    # Phase A: Telekom-/Datenschutz-/Gewerbe-Gesetze duerfen NICHT mehr als
+    # Impressum durchgehen (Korpus enthaelt kein echtes Impressumsrecht ausser
+    # TMG/MStV). Siehe Audit 2026-06-09.
+    assert reg.use_case_for_regulation("Telekommunikationsgesetz Oesterreich") \
+        == "telekommunikation"
+    assert reg.use_case_for_regulation("DSK OH Telemedien") == "dse"
+    assert reg.use_case_for_regulation("Gewerbeordnung (GewO)") == "handelsrecht"
+    # Die echten Impressum-Quellen bleiben Impressum:
+    assert reg.use_case_for_regulation("TMG") == "impressum"
+    assert reg.use_case_for_regulation("AT Mediengesetz") == "impressum"
+
+
 def test_regulation_mapper_abgb_before_bgb():
     # 'ABGB' enthaelt 'bgb' — die abgb-Regel MUSS zuerst greifen.
     assert reg.use_case_for_regulation("AT ABGB") == "handelsrecht"