diff --git a/check-linuxcnc-rs274-source-map.sh b/check-linuxcnc-rs274-source-map.sh
index 881a3a2..39ece27 100755
--- a/check-linuxcnc-rs274-source-map.sh
+++ b/check-linuxcnc-rs274-source-map.sh
@@ -5,8 +5,8 @@ cd "$(dirname "$0")"
 
 # LinuxCNC source basis: this guard keeps the local source map aligned with the
 # LinuxCNC-root relative rs274 manifests that drive native and WASM source-link
-# probes. It validates documentation/manifest drift only; it does not interpret
-# CNC behavior.
+# probes. It validates documentation/manifest drift only; it does not add CNC
+# behavior, expand smoke parsing, or interpret G-code.
 python3 - <<'PY'
 from pathlib import Path
 
@@ -77,4 +77,26 @@ for section, expected_entries in expected.items():
         raise SystemExit(
             f"docs/linuxcnc-rs274-source-map.md {labels[section]} list no longer matches source manifest"
         )
+
+for phrase in [
+    "must not add CNC behavior",
+    "must not expand the temporary smoke parser",
+    "source coverage only",
+    "must not become browser API fields",
+    "temporary smoke parser fallback behavior",
+    "Browser-hostile dependencies must remain tracked blockers",
+    "./check-linuxcnc-rs274-source-map.sh",
+    "does not interpret G-code",
+]:
+    if phrase not in source_map:
+        raise SystemExit(f"docs/linuxcnc-rs274-source-map.md missing boundary phrase: {phrase}")
+
+for entry in [
+    "test-native.sh",
+    "test-linuxcnc-source-link.sh",
+    "build-wasm.sh",
+]:
+    text = Path(entry).read_text(encoding="utf-8")
+    if "./check-linuxcnc-rs274-source-map.sh" not in text:
+        raise SystemExit(f"{entry} must run ./check-linuxcnc-rs274-source-map.sh")
 PY
diff --git a/docs/linuxcnc-rs274-source-map.md b/docs/linuxcnc-rs274-source-map.md
index 6a182ed..428adaa 100644
--- a/docs/linuxcnc-rs274-source-map.md
+++ b/docs/linuxcnc-rs274-source-map.md
@@ -1,6 +1,8 @@
 # LinuxCNC rs274 source map
 
-This is the working map for moving from native `librs274` linking to source-level compilation and then to wasm.
+This is the working map for moving from native `librs274` linking to
+source-level compilation and then to wasm. It is a source-manifest guard only;
+it must not add CNC behavior and must not expand the temporary smoke parser.
 
 ## Compile assumptions
 
@@ -176,6 +178,33 @@ the browser-safe shims and manifest completeness checks:
 - persistent parameter file writes.
 - dynamic INI/HAL queries.
 
+## Boundaries
+
+- Native and WASM source lists in this document must match
+  `linuxcnc-rs274-source-files.txt` and
+  `linuxcnc-rs274-wasm-source-files.txt` exactly.
+- Python binding modules, WASM-blocked sources, and WASM-blocked headers are
+  source coverage only.
+- They must not become browser API fields or temporary smoke parser fallback behavior.
+- Browser-hostile dependencies must remain tracked blockers until they are
+  ported, trimmed, wrapped, or replaced by source-backed browser-safe LinuxCNC
+  adaptations.
+- `test-native.sh`, `test-linuxcnc-source-link.sh`, and `build-wasm.sh` must
+  run `./check-linuxcnc-rs274-source-map.sh` before consuming generated native
+  objects, source-linked LinuxCNC objects, or browser artifacts.
+- The RS274 source-map guard validates LinuxCNC source ownership and manifest
+  drift only; it does not interpret G-code.
+
+## Checks
+
+Run:
+
+```bash
+./check-linuxcnc-rs274-source-map.sh
+./test-native.sh
+./test-linuxcnc-source-link.sh
+```
+
 The wasm-safe runtime now constructs its detached `EMC_STAT` through LinuxCNC
 `src/emc/nml_intf/emcops.cc`. The singleton follows LinuxCNC
 `src/emc/sai/dummyemcstat.cc`, and the required `NMLmsg`/`RCS_STAT_MSG`