diff --git a/patterns/default.yaml b/patterns/default.yaml
index 54c87a3..ab6f1d4 100644
--- a/patterns/default.yaml
+++ b/patterns/default.yaml
@@ -211,10 +211,10 @@ patterns:
     domain: media
     description: Plex EasyAudioEncoder (EAC3 Dolby audio transcoder) crashed — service restart required
 
-  # - name: avcx_device_error
+  # - name: ext_device_error
   #   pattern: "ERR-\d{4}"
   #   severity: ERROR
-  #   description: AVCX device error code
+  #   description: vendor device structured error code
 
   # ── VPN / tunnel patterns ──────────────────────────────────────────────────
 
diff --git a/scripts/gen_corpus.py b/scripts/gen_corpus.py
index 406c863..c1a4ed4 100644
--- a/scripts/gen_corpus.py
+++ b/scripts/gen_corpus.py
@@ -12,7 +12,7 @@ Output tree:
     <out>/journald/system.jsonl   — systemd/kernel journald JSON
     <out>/docker/services.jsonl   — containerised app stdout
     <out>/qbittorrent/qbt.log     — hotio-format qBittorrent log
-    <out>/avcx/device.log         — AVCX device plaintext log
+    <out>/ext_device/device.log    — vendor device plaintext log
 """
 from __future__ import annotations
 
@@ -191,7 +191,7 @@ _QBT_MESSAGES: dict[str, list[str]] = {
     ],
 }
 
-_AVCX_CODES: dict[str, list[str]] = {
+_EXT_DEVICE_CODES: dict[str, list[str]] = {
     "INFO": [
         "SYS-0100 Device boot complete, firmware v{n}.{n}.{n}",
         "SYS-0101 Sensor array calibration OK",
@@ -307,13 +307,13 @@ def gen_qbittorrent(path: Path, start: datetime, end: datetime, rng: random.Rand
     return lines
 
 
-def gen_avcx(path: Path, start: datetime, end: datetime, rng: random.Random, error_rate: float) -> int:
-    """Emit AVCX device plaintext log (ISO timestamp + level + ERR/SYS/NET code + message)."""
+def gen_ext_device(path: Path, start: datetime, end: datetime, rng: random.Random, error_rate: float) -> int:
+    """Emit vendor device plaintext log (ISO timestamp + level + ERR/SYS/NET code + message)."""
     lines = 0
     with path.open("w") as fh:
         for dt in _ts_seq(start, end, rng):
             severity = _pick_severity(rng, error_rate)
-            msg      = _pick_msg(_AVCX_CODES, severity, rng)
+            msg      = _pick_msg(_EXT_DEVICE_CODES, severity, rng)
             ts_str   = dt.strftime("%Y-%m-%dT%H:%M:%S")
             fh.write(f"{ts_str} [{severity}] {msg}\n")
             lines += 1
@@ -326,7 +326,7 @@ _GENERATORS: list[tuple[str, str, Callable]] = [
     ("journald",    "system.jsonl",  gen_journald),
     ("docker",      "services.jsonl", gen_docker),
     ("qbittorrent", "qbt.log",       gen_qbittorrent),
-    ("avcx",        "device.log",    gen_avcx),
+    ("ext_device",  "device.log",    gen_ext_device),
 ]
 
 
diff --git a/tests/test_gen_corpus.py b/tests/test_gen_corpus.py
index 0a03d75..8328c62 100644
--- a/tests/test_gen_corpus.py
+++ b/tests/test_gen_corpus.py
@@ -31,7 +31,7 @@ class TestOutputStructure:
         assert (tmp_path / "journald" / "system.jsonl").exists()
         assert (tmp_path / "docker"   / "services.jsonl").exists()
         assert (tmp_path / "qbittorrent" / "qbt.log").exists()
-        assert (tmp_path / "avcx"     / "device.log").exists()
+        assert (tmp_path / "ext_device"     / "device.log").exists()
 
     def test_returns_line_counts(self, tmp_path: Path) -> None:
         totals = _run(tmp_path)
@@ -129,12 +129,12 @@ class TestQbittorrentFormat:
         assert severities <= {"INFO", "WARN", "CRITICAL"}
 
 
-# ── AVCX format ────────────────────────────────────────────────────────────────
+# ── Vendor device format ────────────────────────────────────────────────────────────────
 
 class TestAvcxFormat:
     def test_iso_timestamp_prefix(self, tmp_path: Path) -> None:
         _run(tmp_path)
-        lines = (tmp_path / "avcx/device.log").read_text().splitlines()
+        lines = (tmp_path / "ext_device/device.log").read_text().splitlines()
         import re
         pattern = re.compile(r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2} \[.+\] .+$")
         assert all(pattern.match(line) for line in lines[:50])
@@ -142,7 +142,7 @@ class TestAvcxFormat:
     def test_parseable_by_plaintext_glean(self, tmp_path: Path) -> None:
         from app.glean.plaintext import parse
         _run(tmp_path)
-        with (tmp_path / "avcx/device.log").open() as fh:
+        with (tmp_path / "ext_device/device.log").open() as fh:
             entries = list(parse(fh, "test", []))
         assert len(entries) > 0
         # ISO timestamps should parse cleanly