diff --git a/apps/server/src/device-events.ts b/apps/server/src/device-events.ts
index cfbacf8..51255cc 100644
--- a/apps/server/src/device-events.ts
+++ b/apps/server/src/device-events.ts
@@ -24,6 +24,13 @@ export interface DeviceReadEvent {
   readonly deviceId: string; // devices id of the reader/scanner/camera
   readonly value: string; // the ticket id / plate / card number
   readonly kind: "ticket" | "plate" | "qr" | "card";
+  /** The CONFIRMED physical channel the value arrived on, when the reader tags it
+   *  (the DT-008 output prefixes — see routes/qr-reader.ts). `optical` = decoded by
+   *  the barcode/QR engine; `rf` = read from a card/chip. Undefined = legacy reader
+   *  with no prefixes configured (channel unknown — flows must not assume). Lets the
+   *  subscription match refuse an OPTICAL decode claiming an RF credential (a printed
+   *  copy of a card's UID must not clone the card). */
+  readonly channel?: "optical" | "rf";
   readonly at: string; // ISO-8601
 }
 
diff --git a/apps/server/src/read-dispatch-filter.test.ts b/apps/server/src/read-dispatch-filter.test.ts
new file mode 100644
index 0000000..f3a1c01
--- /dev/null
+++ b/apps/server/src/read-dispatch-filter.test.ts
@@ -0,0 +1,103 @@
+import { randomUUID } from "node:crypto";
+import { beforeEach, describe, expect, it } from "vitest";
+import { devices, deviceEvents as deviceEventsTable, ledgerEvents, subscriptionCredentials, type Db } from "@parking/db";
+import { createTestDb } from "@parking/db/testing";
+import { ReadDispatcher } from "./read-dispatch.js";
+import { ExitFlow } from "./exit-flow.js";
+import { SubscriptionFlow } from "./subscription-flow.js";
+import type { DeviceReadEvent } from "./device-events.js";
+import { makeLog, silentLogger } from "./test-helpers.js";
+
+// STRUCTURAL FILTER at the dispatcher (2026-07-04): a reader value that matched
+// nothing AND can't possibly be a credential we issued (no ticket Luhn shape, no
+// SUB-/SUBSESS- prefix, not a confirmed-RF read) is refused with UNSIGNED telemetry
+// instead of reaching the exit flow and signing a noSession anomaly. Born from the
+// park-buzi phantom optical decodes: red "who is exiting?" rows for NOBODY train the
+// operator to ignore the signed feed. Anything plausibly ours STILL signs normally.
+
+let db: Db;
+let dispatcher: ReadDispatcher;
+
+const READER = "reader-exit";
+
+beforeEach(() => {
+  ({ db } = createTestDb());
+  db.insert(devices).values({
+    id: "ctl-exit",
+    category: "access",
+    driverId: "stub-access",
+    config: { relays: [{ relay: 1, direction: "exit" }] },
+    enabled: true,
+  }).run();
+  db.insert(devices).values({
+    id: READER,
+    category: "reader",
+    driverId: "dingtian-qr-reader",
+    config: { serial: "H05MA5B0", direction: "exit" },
+    enabled: true,
+  }).run();
+  const log = makeLog(db);
+  dispatcher = new ReadDispatcher(db, new ExitFlow(db, log, silentLogger()), new SubscriptionFlow(db, log, silentLogger()), silentLogger());
+});
+
+function read(value: string, opts: { kind?: DeviceReadEvent["kind"]; channel?: DeviceReadEvent["channel"] } = {}): DeviceReadEvent {
+  return {
+    driverId: "dingtian-qr-reader",
+    deviceId: READER,
+    value,
+    kind: opts.kind ?? "qr",
+    ...(opts.channel ? { channel: opts.channel } : {}),
+    at: new Date().toISOString(),
+  };
+}
+
+const ledger = () => db.select().from(ledgerEvents).all();
+const unrecognized = () =>
+  db.select().from(deviceEventsTable).all()
+    .map((r) => r.detail as { unrecognizedRead?: boolean; value?: string })
+    .filter((d) => d.unrecognizedRead === true);
+
+describe("read-dispatch structural filter", () => {
+  it("phantom 6-digit optical decode → refused, telemetry only, NOTHING signed", async () => {
+    const out = await dispatcher.dispatch(read("999459", { channel: "optical" }));
+    expect(out.accepted).toBe(false);
+    expect(out.reason).toMatch(/unrecognized/);
+    expect(ledger()).toHaveLength(0); // the whole point: no red row in the feed
+    expect(unrecognized()).toHaveLength(1);
+    expect(unrecognized()[0].value).toBe("999459");
+  });
+
+  it("legacy untagged garbage ('C') → filtered too (works before prefixes are deployed)", async () => {
+    const out = await dispatcher.dispatch(read("C"));
+    expect(out.accepted).toBe(false);
+    expect(ledger()).toHaveLength(0);
+    expect(unrecognized()).toHaveLength(1);
+  });
+
+  it("Luhn-valid unknown ticket → NOT filtered: the exit flow signs the noSession anomaly", async () => {
+    const out = await dispatcher.dispatch(read("00000000000")); // valid shape, no session
+    expect(out.accepted).toBe(false);
+    expect(unrecognized()).toHaveLength(0);
+    const anomalies = ledger().filter((r) => r.type === "anomaly");
+    expect(anomalies.length).toBeGreaterThan(0); // a real probe stays in the signed feed
+  });
+
+  it("unknown card on a CONFIRMED RF channel → NOT filtered (a physical card is a real event)", async () => {
+    await dispatcher.dispatch(read("1A86A158", { kind: "card", channel: "rf" }));
+    expect(unrecognized()).toHaveLength(0);
+    expect(ledger().filter((r) => r.type === "anomaly").length).toBeGreaterThan(0);
+  });
+
+  it("unknown SUB- code → NOT filtered (our own prefix = an interesting probe)", async () => {
+    await dispatcher.dispatch(read("SUB-DOESNOTEXIST", { channel: "optical" }));
+    expect(unrecognized()).toHaveLength(0);
+    expect(ledger().filter((r) => r.type === "anomaly").length).toBeGreaterThan(0);
+  });
+
+  it("an ENROLLED credential is matched BEFORE the filter (never hidden by it)", async () => {
+    // A card UID that would fail every shape test — enrolled, so it must still match.
+    db.insert(subscriptionCredentials).values({ id: randomUUID(), subscriptionId: "sub-1", kind: "rf", value: "999459" }).run();
+    await dispatcher.dispatch(read("999459")); // legacy untagged read of it
+    expect(unrecognized()).toHaveLength(0); // reached the subscription flow, not the filter
+  });
+});
diff --git a/apps/server/src/read-dispatch.ts b/apps/server/src/read-dispatch.ts
index 9beebf9..03dd856 100644
--- a/apps/server/src/read-dispatch.ts
+++ b/apps/server/src/read-dispatch.ts
@@ -1,7 +1,9 @@
-import { devices, eq, type Db } from "@parking/db";
+import { randomUUID } from "node:crypto";
+import { devices, deviceEvents as deviceEventsTable, eq, type Db } from "@parking/db";
 import type { FastifyBaseLogger } from "fastify";
 import type { DeviceReadEvent, ReadOutcome } from "./device-events.js";
 import type { ExitFlow } from "./exit-flow.js";
+import { validateTicketCode } from "./entry-flow.js";
 import type { SubscriptionFlow } from "./subscription-flow.js";
 import { relayForDevice } from "./device-resolve.js";
 
@@ -17,6 +19,22 @@ import { relayForDevice } from "./device-resolve.js";
 // it opens that exact barrier. An "entry" reader drives the entry side, an "exit"
 // reader the exit side; "both" defers to the flow's own inference (subscription:
 // session state; transient: exit).
+//
+// STRUCTURAL FILTER (2026-07-04, operator-requested). The DT-008's scan engine
+// false-decodes sunlight stripe patterns into short garbage codes (phantom reads —
+// see wiki/entities/dingtian-dt008-reader.md), and each one was reaching the exit
+// flow and signing an exit.refused.noSession anomaly: red "who is trying to exit?"
+// rows for NOBODY, training the operator to ignore the feed (alarm fatigue is the
+// adversary's friend). So a reader value that matched nothing AND cannot possibly be
+// a credential we issued is dropped to UNSIGNED telemetry (device_events, still
+// auditable) instead of the signed ledger. "Possibly ours" stays deliberately wide —
+// any of these still reaches the flows and signs the normal refusal anomaly:
+//   - a Luhn-valid ticket shape (validateTicketCode — a forged/expired ticket is a
+//     real probe),
+//   - our issued-code prefixes (SUB- / SUBSESS-),
+//   - ANY read on a CONFIRMED RF channel (a physically present card, enrolled or
+//     not, is a real event — RF is never sun noise),
+//   - plates (different population; never shape-filtered here).
 
 export class ReadDispatcher {
   readonly #db: Db;
@@ -45,6 +63,20 @@ export class ReadDispatcher {
     if (sub) {
       return this.#subscription.run(resolved, e, sub);
     }
+
+    // Matched nothing — if the value can't even BE one of ours, it's scanner noise
+    // (phantom optical decode): refuse with unsigned telemetry, keep the signed feed
+    // for events that involve an actual credential or an actual card.
+    if ((e.kind === "qr" || e.kind === "card" || e.kind === "ticket") && !plausibleCredential(e)) {
+      this.#recordUnrecognized(e);
+      this.#logger.info(`read filtered (not a credential shape): '${e.value}' from ${e.deviceId}${e.channel ? ` ch=${e.channel}` : ""}`);
+      return {
+        accepted: false,
+        direction: resolved.direction === "entry" ? "entry" : "exit",
+        reason: "unrecognized code (no credential shape — telemetry only)",
+      };
+    }
+
     // Not a subscription → transient ticket exit. An ENTRY reader can't produce a
     // transient exit (transient entry is the button flow, not a reader), so reject+log
     // rather than treat an entry scan as an exit.
@@ -53,4 +85,39 @@ export class ReadDispatcher {
     }
     return this.#exit.handleAt(resolved, e);
   }
+
+  /** Unsigned telemetry for a filtered read — auditable in device_events, out of the
+   *  signed feed. Mirrors the entry flow's suppressed-press pattern. */
+  #recordUnrecognized(e: DeviceReadEvent): void {
+    try {
+      this.#db
+        .insert(deviceEventsTable)
+        .values({
+          id: randomUUID(),
+          deviceId: e.deviceId,
+          category: "reader",
+          kind: "read",
+          detail: {
+            unrecognizedRead: true,
+            value: e.value,
+            readKind: e.kind,
+            ...(e.channel ? { channel: e.channel } : {}),
+            reason: "no credential shape (phantom decode / garbage scan)",
+          },
+          occurredAt: e.at,
+        })
+        .run();
+    } catch (err) {
+      this.#logger.error(`unrecognized-read telemetry insert failed: ${(err as Error).message}`);
+    }
+  }
+}
+
+/** Could this reader value possibly be a credential WE issued (or a real card)?
+ *  Deliberately WIDE — only shapes that can't be anything of ours are filtered. */
+function plausibleCredential(e: DeviceReadEvent): boolean {
+  if (e.channel === "rf") return true; // a physically present card — never sun noise
+  if (validateTicketCode(e.value)) return true; // ticket shape (10–14 digits + Luhn)
+  if (/^SUB(SESS)?-/.test(e.value)) return true; // our subscription QR / window-slip ids
+  return false;
 }
diff --git a/apps/server/src/routes/qr-reader-channel.test.ts b/apps/server/src/routes/qr-reader-channel.test.ts
new file mode 100644
index 0000000..9d84c15
--- /dev/null
+++ b/apps/server/src/routes/qr-reader-channel.test.ts
@@ -0,0 +1,101 @@
+import Fastify from "fastify";
+import { beforeEach, afterEach, describe, expect, it } from "vitest";
+import { devices, type Db } from "@parking/db";
+import { createTestDb } from "@parking/db/testing";
+import { qrReaderRoutes, splitChannel } from "./qr-reader.js";
+import { CredentialCapture } from "../credential-capture.js";
+import type { DeviceReadEvent, ReadOutcome } from "../device-events.js";
+import type { ReadDispatcher } from "../read-dispatch.js";
+
+// CHANNEL TAGGING (2026-07-04): the DT-008's "QRCode Output Prefix" / "Card Output
+// Prefix" (vendor tool) mark which engine produced a push — Q: = optical, K: = RF.
+// The route strips the prefix, tags the read's confirmed channel, and enrollment
+// capture stores the BARE value. Unprefixed reads stay the legacy untagged shape so
+// an unconfigured reader keeps working. These tests pin the route-side contract;
+// the match-side enforcement is pinned in ../subscription-channel.test.ts.
+
+const SERIAL = "H05MA5B0";
+const READER_ID = "reader-exit";
+
+let db: Db;
+let app: ReturnType<typeof Fastify>;
+let capture: CredentialCapture;
+let seen: DeviceReadEvent[];
+
+/** Dispatcher stub: records the event the route built, always rejects. */
+const fakeDispatcher = {
+  dispatch: async (e: DeviceReadEvent): Promise<ReadOutcome> => {
+    seen.push(e);
+    return { accepted: false, reason: "test" };
+  },
+} as unknown as ReadDispatcher;
+
+beforeEach(async () => {
+  ({ db } = createTestDb());
+  db.insert(devices).values({
+    id: READER_ID,
+    category: "reader",
+    driverId: "dingtian-qr-reader",
+    config: { serial: SERIAL },
+    enabled: true,
+  }).run();
+  seen = [];
+  capture = new CredentialCapture();
+  app = Fastify({ logger: false });
+  await qrReaderRoutes(app as never, db, fakeDispatcher, capture);
+});
+
+afterEach(async () => {
+  await app.close();
+});
+
+const scan = (cardid: string) =>
+  app.inject({ method: "GET", url: `/qa/mcardsea.php?cardid=${encodeURIComponent(cardid)}&cjihao=${SERIAL}&mjihao=1&status=10` });
+
+describe("splitChannel", () => {
+  it("K: prefix → bare value, kind card, channel rf", () => {
+    expect(splitChannel("K:86A158")).toEqual({ value: "86A158", kind: "card", channel: "rf" });
+  });
+  it("Q: prefix → bare value, kind qr, channel optical", () => {
+    expect(splitChannel("Q:12345678901")).toEqual({ value: "12345678901", kind: "qr", channel: "optical" });
+  });
+  it("no prefix → value untouched, legacy untagged qr", () => {
+    expect(splitChannel("86A158")).toEqual({ value: "86A158", kind: "qr" });
+  });
+});
+
+describe("qr-reader route channel tagging", () => {
+  it("card-prefixed push dispatches a stripped, rf-tagged read", async () => {
+    const res = await scan("K:86A158");
+    expect(res.statusCode).toBe(200);
+    expect(seen).toHaveLength(1);
+    expect(seen[0]).toMatchObject({ value: "86A158", kind: "card", channel: "rf", deviceId: READER_ID });
+  });
+
+  it("qr-prefixed push dispatches a stripped, optical-tagged read", async () => {
+    await scan("Q:00000000000");
+    expect(seen[0]).toMatchObject({ value: "00000000000", kind: "qr", channel: "optical" });
+  });
+
+  it("unprefixed push stays legacy: kind qr, no channel", async () => {
+    await scan("86A158");
+    expect(seen[0]).toMatchObject({ value: "86A158", kind: "qr" });
+    expect(seen[0].channel).toBeUndefined();
+  });
+
+  it("a bare prefix (empty value after strip) dispatches nothing", async () => {
+    await scan("K:");
+    expect(seen).toHaveLength(0);
+  });
+
+  it("enrollment capture stores the BARE value, not the prefixed one", async () => {
+    capture.arm(READER_ID);
+    const res = await scan("K:86A158");
+    expect(seen).toHaveLength(0); // intercepted — never dispatched to the access flow
+    const state = capture.state();
+    expect(state.status).toBe("captured");
+    if (state.status === "captured") expect(state.value).toBe("86A158");
+    // Beeps "ok" so the operator knows the card was read.
+    expect(res.json().data[0].status).toBe(1);
+  });
+});
diff --git a/apps/server/src/routes/qr-reader.ts b/apps/server/src/routes/qr-reader.ts
index 8962a0d..b5f14a3 100644
--- a/apps/server/src/routes/qr-reader.ts
+++ b/apps/server/src/routes/qr-reader.ts
@@ -27,6 +27,36 @@ interface ReaderQuery {
   time?: string;
 }
 
+// ── CHANNEL TAGGING (2026-07-04) ────────────────────────────────────────────────
+// The DT-008 push carries one opaque `cardid` whether its OPTICAL engine decoded a
+// QR/barcode or its RF engine read a card — the server can't tell them apart. That
+// enabled a cheap clone: print a card's UID (often written on the card face) as a
+// barcode and the optical decode matches the RF credential. Fix: the vendor tool's
+// "QRCode Output Prefix" / "Card Output Prefix" are set to the markers below on every
+// reader; the route strips the prefix and tags the read's confirmed channel, and the
+// subscription match refuses a channel-mismatched credential. A read with NO prefix
+// stays the legacy untagged shape (kind "qr", channel undefined) so an unconfigured
+// reader keeps working — the enforcement only bites where prefixes are deployed.
+// ⚠️ Prefixes must MATCH the vendor tool; also FREEZE "Card Input format" (6H) — that
+// setting defines the UID shape we enroll. See wiki/entities/dingtian-dt008-reader.md.
+const QR_CHANNEL_PREFIX = process.env.READER_QR_PREFIX ?? "Q:";
+const CARD_CHANNEL_PREFIX = process.env.READER_CARD_PREFIX ?? "K:";
+
+/** Split a raw pushed `cardid` into its bare value + confirmed channel (if prefixed). */
+export function splitChannel(raw: string): {
+  value: string;
+  kind: "qr" | "card";
+  channel?: "optical" | "rf";
+} {
+  if (CARD_CHANNEL_PREFIX.length > 0 && raw.startsWith(CARD_CHANNEL_PREFIX)) {
+    return { value: raw.slice(CARD_CHANNEL_PREFIX.length), kind: "card", channel: "rf" };
+  }
+  if (QR_CHANNEL_PREFIX.length > 0 && raw.startsWith(QR_CHANNEL_PREFIX)) {
+    return { value: raw.slice(QR_CHANNEL_PREFIX.length), kind: "qr", channel: "optical" };
+  }
+  return { value: raw, kind: "qr" }; // legacy: unprefixed reader, channel unknown
+}
+
 export async function qrReaderRoutes(
   app: FastifyInstance,
   db: Db,
@@ -55,6 +85,7 @@ export async function qrReaderRoutes(
     // See wiki/sources/qrcode-sdk.md, entities/dingtian-dt008-reader.md.
     reply.header("connection", "close");
     const cardid = (q.cardid ?? "").trim();
+    const scan = splitChannel(cardid); // bare value + confirmed channel (if prefixed)
     const mjihao = q.mjihao != null ? Number(q.mjihao) : 0;
     const serial = (q.cjihao ?? "").trim();
 
@@ -65,35 +96,37 @@ export async function qrReaderRoutes(
     const deviceId = matchedRowId ?? serial;
 
     let accepted = false;
-    if (cardid) {
+    if (scan.value) {
       // ENROLLMENT INTERCEPT: if THIS reader is armed for credential capture, grab the
       // value for the subscription form and do NOT run the access flow (we must not
       // open a barrier for a card being enrolled). Single-shot — capture auto-disarms.
       // Reads from the OTHER reader are untouched and dispatch normally below.
-      if (capture.tryConsume(deviceId, cardid)) {
-        app.log.info(`CAPTURE serial=${serial || "?"} device=${matchedRowId ? matchedRowId.slice(0, 8) : "?"} value=${cardid}`);
+      // Captured BARE (prefix stripped) so enrolled values match future stripped reads.
+      if (capture.tryConsume(deviceId, scan.value)) {
+        app.log.info(`CAPTURE serial=${serial || "?"} device=${matchedRowId ? matchedRowId.slice(0, 8) : "?"} value=${scan.value}${scan.channel ? ` ch=${scan.channel}` : ""}`);
         accepted = true; // beep "ok" so the operator knows the card was read
       } else {
       const read: DeviceReadEvent = {
         driverId: "dingtian-qr-reader",
         deviceId,
-        value: cardid,
-        kind: "qr",
+        value: scan.value,
+        kind: scan.kind,
+        ...(scan.channel ? { channel: scan.channel } : {}),
         at: new Date().toISOString(),
       };
       try {
         const outcome = await dispatcher.dispatch(read);
         accepted = outcome.accepted;
         // Per-read diagnostic: which reader (serial) sent it, which configured device
-        // it mapped to, and the verdict — so a barrier/serial mismatch is visible in
-        // the logs (e.g. an entry-side scan resolving to the exit relay).
+        // it mapped to, the confirmed channel (if prefixed), and the verdict — so a
+        // barrier/serial mismatch or a channel anomaly is visible in the logs.
         app.log.info(
           `READ serial=${serial || "?"} → device=${matchedRowId ? matchedRowId.slice(0, 8) : "UNASSIGNED"} ` +
-            `card=${cardid} verdict=${accepted ? "ACCEPT" : "REJECT"}${outcome.direction ? ` dir=${outcome.direction}` : ""}` +
+            `card=${scan.value}${scan.channel ? ` ch=${scan.channel}` : ""} verdict=${accepted ? "ACCEPT" : "REJECT"}${outcome.direction ? ` dir=${outcome.direction}` : ""}` +
             `${accepted ? "" : ` reason="${outcome.reason ?? "?"}"`}`,
         );
       } catch (err) {
-        app.log.error(`QR dispatch failed for ${cardid}: ${(err as Error).message}`);
+        app.log.error(`QR dispatch failed for ${scan.value}: ${(err as Error).message}`);
       }
       }
     }
diff --git a/apps/server/src/subscription-channel.test.ts b/apps/server/src/subscription-channel.test.ts
new file mode 100644
index 0000000..0ea0d3f
--- /dev/null
+++ b/apps/server/src/subscription-channel.test.ts
@@ -0,0 +1,88 @@
+import { randomUUID } from "node:crypto";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { ledgerEvents, subscriptionCredentials, type Db } from "@parking/db";
+import { createTestDb } from "@parking/db/testing";
+import { SubscriptionFlow } from "./subscription-flow.js";
+import type { DeviceReadEvent } from "./device-events.js";
+import { makeLog, silentLogger } from "./test-helpers.js";
+
+// CHANNEL AGREEMENT in SubscriptionFlow.match (2026-07-04): when the reader CONFIRMED
+// the physical channel (DT-008 output prefixes → DeviceReadEvent.channel), the
+// credential kind must agree. An OPTICAL decode claiming an RF credential is the
+// cheap clone (print the card's UID as a barcode) — refused + ONE signed anomaly.
+// Legacy untagged reads (channel undefined) match as before, so readers without
+// prefixes keep working.
+
+let db: Db;
+let flow: SubscriptionFlow;
+
+const SUB = "sub-1";
+const CARD_UID = "86A158";
+const QR_CODE = "SUB-TESTQR";
+
+beforeEach(() => {
+  ({ db } = createTestDb());
+  db.insert(subscriptionCredentials).values({ id: randomUUID(), subscriptionId: SUB, kind: "rf", value: CARD_UID }).run();
+  db.insert(subscriptionCredentials).values({ id: randomUUID(), subscriptionId: SUB, kind: "qr", value: QR_CODE }).run();
+  flow = new SubscriptionFlow(db, makeLog(db), silentLogger());
+});
+
+function read(value: string, opts: { kind?: DeviceReadEvent["kind"]; channel?: DeviceReadEvent["channel"] } = {}): DeviceReadEvent {
+  return {
+    driverId: "dingtian-qr-reader",
+    deviceId: "reader-1",
+    value,
+    kind: opts.kind ?? "qr",
+    ...(opts.channel ? { channel: opts.channel } : {}),
+    at: new Date().toISOString(),
+  };
+}
+
+const anomalies = () =>
+  db.select().from(ledgerEvents).all().filter((r) => r.type === "anomaly");
+
+describe("subscription match — credential channel agreement", () => {
+  it("OPTICAL read of an RF card's UID → no match + signed channelMismatch anomaly (the clone)", async () => {
+    const m = flow.match(read(CARD_UID, { kind: "qr", channel: "optical" }));
+    expect(m).toBeNull();
+    await vi.waitFor(() => expect(anomalies()).toHaveLength(1)); // append is fire-and-forget
+    expect(anomalies()[0].identity).toBe(SUB);
+    expect(anomalies()[0].payload).toMatchObject({
+      reasonCode: "sub.refused.channelMismatch",
+      channelMismatch: true,
+      credentialKind: "rf",
+      channel: "optical",
+      value: CARD_UID,
+    });
+  });
+
+  it("RF read of the same card → matches (via card), nothing signed", () => {
+    const m = flow.match(read(CARD_UID, { kind: "card", channel: "rf" }));
+    expect(m).toMatchObject({ subscriptionId: SUB, via: "card" });
+    expect(anomalies()).toHaveLength(0);
+  });
+
+  it("legacy untagged read of the card → still matches (unprefixed readers keep working)", () => {
+    const m = flow.match(read(CARD_UID)); // kind qr, channel undefined — today's shape
+    expect(m).toMatchObject({ subscriptionId: SUB, via: "card" });
+    expect(anomalies()).toHaveLength(0);
+  });
+
+  it("OPTICAL read of a QR credential → matches (the legit path)", () => {
+    const m = flow.match(read(QR_CODE, { kind: "qr", channel: "optical" }));
+    expect(m).toMatchObject({ subscriptionId: SUB, via: "qr" });
+  });
+
+  it("RF read claiming a QR credential → refused symmetrically (mis-encoded clone tag)", async () => {
+    const m = flow.match(read(QR_CODE, { kind: "card", channel: "rf" }));
+    expect(m).toBeNull();
+    await vi.waitFor(() => expect(anomalies()).toHaveLength(1));
+    expect(anomalies()[0].payload).toMatchObject({ credentialKind: "qr", channel: "rf" });
+  });
+
+  it("unknown value → plain no-match, no anomaly (a phantom/typo is not a clone attempt)", () => {
+    const m = flow.match(read("999459", { kind: "qr", channel: "optical" }));
+    expect(m).toBeNull();
+    expect(anomalies()).toHaveLength(0);
+  });
+});
diff --git a/apps/server/src/subscription-flow.ts b/apps/server/src/subscription-flow.ts
index 405ce69..e777583 100644
--- a/apps/server/src/subscription-flow.ts
+++ b/apps/server/src/subscription-flow.ts
@@ -77,6 +77,40 @@ export class SubscriptionFlow {
       .where(eq(subscriptionCredentials.value, e.value))
       .get();
     if (cred) {
+      // CHANNEL AGREEMENT (clone defense, 2026-07-04). When the reader CONFIRMED the
+      // physical channel (DT-008 output prefixes), the credential kind must agree: an
+      // OPTICAL decode may not claim an RF credential — otherwise printing a card's
+      // UID (often written on the card face) as a barcode clones the card. Symmetric
+      // for an RF read claiming a QR credential (a mis-encoded clone tag). A legacy
+      // untagged read (channel undefined) matches as before — enforcement only bites
+      // where prefixes are deployed. The attempt itself is a fraud signal → signed
+      // anomaly, then treated as no-match (the flows refuse it as unknown).
+      const mismatch =
+        (e.channel === "optical" && cred.kind === "rf") ||
+        (e.channel === "rf" && cred.kind === "qr");
+      if (mismatch) {
+        this.#logger.warn(
+          `credential channel mismatch: ${cred.kind} credential '${e.value}' presented via ${e.channel} (sub ${cred.subscriptionId}) — possible clone`,
+        );
+        void this.#log
+          .append({
+            type: "anomaly",
+            identity: cred.subscriptionId,
+            payload: {
+              ...reasonPayload("sub.refused.channelMismatch", {
+                credentialKind: cred.kind,
+                channel: e.channel === "optical" ? "optical" : "rf",
+              }),
+              channelMismatch: true,
+              credentialKind: cred.kind,
+              channel: e.channel,
+              value: e.value,
+              deviceId: e.deviceId,
+            },
+          })
+          .catch((err) => this.#logger.error(`channel-mismatch anomaly append failed: ${(err as Error).message}`));
+        return null;
+      }
       return { subscriptionId: cred.subscriptionId, carKey: e.value, via: cred.kind === "qr" ? "qr" : "card" };
     }
     // Plate binding: a read plate that matches a subscription's bound plate is an identity.
diff --git a/apps/web/src/lib/i18n/en.ts b/apps/web/src/lib/i18n/en.ts
index a608ad9..4c5168a 100644
--- a/apps/web/src/lib/i18n/en.ts
+++ b/apps/web/src/lib/i18n/en.ts
@@ -299,6 +299,7 @@ export const en: Catalog = {
     "sub.refused.noSession": "Subscription exit with no open session (already out / never entered)",
     "sub.refused.atCapacity": "Subscription refused — at capacity ({{inUse}}/{{max}} cars in)",
     "sub.refused.unpaidWindow": "Exit refused — out-of-window charge unpaid ({{amount}} {{currency}}); pay at the booth",
+    "sub.refused.channelMismatch": "Credential refused — a {{credentialKind}} credential arrived via the {{channel}} channel (possible cloned credential)",
     "void.ticketCancelled": "Ticket cancelled — {{reason}}",
     "setup.relayTest": "Relay test — admin {{operator}} pulsed relay {{relay}} on controller {{controller}} from Setup",
   },
diff --git a/apps/web/src/lib/i18n/sq.ts b/apps/web/src/lib/i18n/sq.ts
index 864c4cb..01239b9 100644
--- a/apps/web/src/lib/i18n/sq.ts
+++ b/apps/web/src/lib/i18n/sq.ts
@@ -302,6 +302,7 @@ export const sq = {
     "sub.refused.noSession": "Dalje me abonim pa sesion të hapur (tashmë jashtë / nuk ka hyrë kurrë)",
     "sub.refused.atCapacity": "Abonimi u refuzua — në kapacitet ({{inUse}}/{{max}} makina brenda)",
     "sub.refused.unpaidWindow": "Dalja u refuzua — detyrim jashtë orarit i papaguar ({{amount}} {{currency}}); paguaje në kabinë",
+    "sub.refused.channelMismatch": "Kredenciali u refuzua — kredencial {{credentialKind}} i paraqitur në kanalin {{channel}} (kredencial i mundshëm i klonuar)",
     "void.ticketCancelled": "Bileta u anulua — {{reason}}",
     "setup.relayTest": "Test releje — admini {{operator}} aktivizoi relenë {{relay}} te kontrolluesi {{controller}} nga Konfigurimi",
   },
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
index 98f31d2..e925c4d 100644
--- a/packages/shared/src/index.ts
+++ b/packages/shared/src/index.ts
@@ -405,6 +405,10 @@ export const REASON_CODES = [
   // a subscriber owes an out-of-window (early-entry / late-exit) transient charge and
   // hasn't paid it — exit is gated until they settle (the tariff-bridge gate).
   "sub.refused.unpaidWindow",
+  // a credential value arrived on the WRONG physical channel (e.g. an RF card's UID
+  // presented as a printed barcode — a cloned-credential attempt). Channel comes from
+  // the reader's output prefixes; see wiki/entities/dingtian-dt008-reader.md.
+  "sub.refused.channelMismatch",
   // a wrongly-printed transient ticket cancelled by the operator (signed void event).
   "void.ticketCancelled",
   // an admin fired a barrier relay from Setup to test the wiring. The physical open is
@@ -443,6 +447,7 @@ export const REASON_EN: Record<ReasonCode, string> = {
   "sub.refused.noSession": "subscription exit with no open session (already out / never entered)",
   "sub.refused.atCapacity": "subscription refused — at capacity ({inUse}/{max} cars in)",
   "sub.refused.unpaidWindow": "exit refused — out-of-window charge unpaid ({amount} {currency} owed); pay at the booth",
+  "sub.refused.channelMismatch": "credential refused — a {credentialKind} credential arrived via the {channel} channel (possible cloned credential)",
   "void.ticketCancelled": "ticket cancelled — {reason}",
   "setup.relayTest": "relay test — admin {operator} pulsed relay {relay} on controller {controller} from Setup",
 };
diff --git a/wiki/entities/dingtian-dt008-reader.md b/wiki/entities/dingtian-dt008-reader.md
index 35116d2..b82bfa8 100644
--- a/wiki/entities/dingtian-dt008-reader.md
+++ b/wiki/entities/dingtian-dt008-reader.md
@@ -120,6 +120,32 @@ host in the **vendor tool**; assign + enter its serial + bind it here.
 - `output` is replied as `0` (Access). Confirm on hardware whether the reader needs `1`/`2` (WG26/34)
   to drive its access line, vs. `0`.
 
+## Channel tagging — output prefixes close the printed-card-clone hole (2026-07-04)
+
+The push carries ONE opaque `cardid` whether the **optical** engine decoded a QR/barcode or the
+**RF** engine read a card — the server couldn't tell. And `SubscriptionFlow.match` matched by
+**value only** (the stored `rf`/`qr` kind was a label). Consequence: printing a card's UID (often
+written on the card face, e.g. `86A158`) as a barcode and holding it up **cloned the RF card** —
+the optical decode matched the RF credential and opened the barrier. In-threat-model and cheap.
+
+**Fix (both sides):**
+- **Reader (vendor tool, both units):** set `QRCode Output Prefix` = `Q:` and `Card Output
+  Prefix` = `K:` (env-overridable server-side: `READER_QR_PREFIX` / `READER_CARD_PREFIX`).
+- **Server:** `routes/qr-reader.ts` strips the prefix and tags the read's confirmed channel
+  (`DeviceReadEvent.channel: "optical"|"rf"`; kind `qr`/`card`). Enrollment capture stores the
+  **bare** value. `SubscriptionFlow.match` then requires **channel agreement**: an optical read
+  may not claim an `rf` credential (and vice versa) — a mismatch is refused AND signs a
+  `sub.refused.channelMismatch` **anomaly** (a clone attempt is a fraud signal). An **unprefixed**
+  read keeps the legacy untagged shape and matches as before — enforcement only bites where
+  prefixes are deployed, so an unconfigured reader never breaks.
+- Bonus: every `READ` log line now carries `ch=optical|rf`, which permanently attributes any
+  future phantom (see below) to its engine.
+
+⚠️ **Two device-side settings are now part of the credential contract** (they live ON the reader,
+not in our DB — re-apply after any factory reset/swap): the two **output prefixes** (must match
+the server's expected `Q:`/`K:`), and **`Card Input format` (currently `6H`)** — it defines the
+UID shape we enroll; changing it later silently orphans every enrolled card.
+
 ## ⚠️ Phantom optical decodes from sunlight patterns (park-buzi, 2026-07-04)
 
 With the site EMPTY (pre-opening, verified live + by snapshot), the **exit reader
@@ -135,11 +161,20 @@ no checksum — any high-contrast stripe pattern of the right proportions "decod
 patterns at a gate: the striped barrier arm, fence/railing shadows sweeping as the sun moves, glare
 bands. RFID noise would instead give repeating UID-shaped values.
 
-**Impact: noise, not risk.** Every phantom was REFUSED fail-closed (`exit.refused.noSession`, a
-signed anomaly — #52–58 in the feed); a phantom can never match a ticket ([[ticket-encoding]] ids
-are 11-digit + Luhn, so a 6-digit read has nothing to match). Do NOT filter "impossible" codes
-server-side — recording every probe of an exit reader is what the anomaly path is for; fix at the
-source instead:
+**Impact: noise, not risk.** Every phantom was REFUSED fail-closed; a phantom can never match a
+ticket ([[ticket-encoding]] ids are 11-digit + Luhn, so a 6-digit read has nothing to match).
+
+**Feed filter (2026-07-04 — supersedes the earlier "do not filter" position).** Initially each
+phantom signed an `exit.refused.noSession` anomaly (#52–58 in the feed) and the position was to
+keep it that way. The operator overruled it, correctly: red "who is trying to exit?" rows for
+NOBODY train the operator to ignore the signed feed — alarm fatigue is the adversary's friend.
+`read-dispatch.ts` now drops a no-match value that **cannot possibly be a credential we issue** to
+UNSIGNED telemetry (`device_events`, `unrecognizedRead:true` — still auditable). "Possibly ours"
+is deliberately WIDE and everything in it still signs the normal refusal anomaly: Luhn-valid
+ticket shapes (a forged ticket is a real probe), `SUB-`/`SUBSESS-` prefixes, ANY read on a
+confirmed-RF channel (a physical card is a real event, never sun noise), and plates (never
+shape-filtered). The filter also works pre-prefix (legacy untagged reads). Still fix at the
+source too:
 
 **Fix (vendor tool, per reader — config lives ON THE DEVICE, not in our DB):** disable every
 symbology except **QR + Code128** (all our credentials); if offered, set **minimum decode length
diff --git a/wiki/log.md b/wiki/log.md
index b06302f..6d743b2 100644
--- a/wiki/log.md
+++ b/wiki/log.md
@@ -2247,3 +2247,28 @@ flip a signed config_change, tickets stamped presenceBypassed, radar-bypass cool
 commissioning pulse, signed barrier_open_command BEFORE the fire so a test open never reads as the
 out-of-band-open fraud signal, saved-controllers-only, radarAlert lamps excluded). Cross-linked
 from [[operator-issued-entry]] (bypass note) and cataloged in index.md.
+
+## [2026-07-04] update | Reader channel tagging: printed-card-clone hole closed
+
+Investigating the phantom scans surfaced a real vulnerability: the DT-008 push is channel-blind
+and SubscriptionFlow.match matched by value only, so printing an RF card's UID (written on the
+card face) as a barcode cloned the card. Fixed with channel tagging: vendor-tool output prefixes
+(Q:/K:) → routes/qr-reader.ts strips + tags DeviceReadEvent.channel (optical|rf) → match requires
+channel agreement, refusing a mismatch + signing a sub.refused.channelMismatch anomaly (a clone
+attempt is a fraud signal). Untagged (unprefixed) reads keep legacy behavior — enforcement only
+bites where prefixes are deployed. Enrollment capture stores bare values. Recorded on
+[[dingtian-dt008-reader]] incl. the two device-side settings now part of the credential contract
+(prefixes + Card Input format 6H — re-apply after factory reset). 14 new tests; suite 272 green.
+
+## [2026-07-04] update | Structural read filter: phantom scans out of the signed feed
+
+Operator-requested reversal of the earlier "do not filter" position (recorded as superseded on
+[[dingtian-dt008-reader]]): phantom decodes were signing exit.refused.noSession anomalies — red
+rows for nobody, training the operator to ignore the feed. read-dispatch.ts now drops a no-match
+reader value that cannot possibly be ours (no ticket Luhn shape, no SUB-/SUBSESS- prefix, not
+confirmed-RF, not a plate) to unsigned device_events telemetry (unrecognizedRead:true). The
+plausibility rule is deliberately wide so every real probe (forged ticket shape, unknown physical
+card, unknown SUB- code) still signs the normal anomaly; enrolled credentials match before the
+filter and can never be hidden by it. Works for legacy unprefixed reads too, so the feed cleans up
+before the vendor-tool visit. 6 new tests; suite 278 green. Also this session: reader channel
+tagging (clone defense) — see the prior entry.