diff --git a/.github/workflows/sanitization.yml b/.github/workflows/sanitization.yml
index c10cdc8..434057f 100644
--- a/.github/workflows/sanitization.yml
+++ b/.github/workflows/sanitization.yml
@@ -24,13 +24,20 @@ jobs:
         with:
           python-version: "3.12"
 
-      - name: Install semantic-layer dep
-        run: pip install anthropic
+      - name: Install deps (semantic layer + self-tests)
+        run: pip install anthropic pytest
 
       - name: Scanner self-tests (deterministic, no key needed)
         run: python -m pytest tests/test_check_sanitization.py -q
 
       - name: Sanitization gate (diff)
+        # The semantic (LLM) layer runs automatically when ANTHROPIC_API_KEY is set
+        # as a repo Actions secret — strongly recommended, since it's the layer that
+        # catches engagement particulars the deterministic regexes can't. Without the
+        # key it skips with a loud warning (deterministic layer still hard-fails on
+        # secrets/PII). To make the semantic layer MANDATORY once your key is wired,
+        # append `--require-semantic` below: the gate then fails closed if the key is
+        # ever missing instead of silently passing deterministic-only.
         env:
           ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
         run: |
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a015f24..c76c183 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -60,9 +60,14 @@ flag is **not** an automatic rejection — it routes the PR to a human maintaine
 makes the call. If your PR is flagged and you believe it's clean, say so in the PR
 description; a maintainer reviews the flagged content and decides.
 
-The semantic layer runs when `ANTHROPIC_API_KEY` is set in CI secrets. Without the
-key it skips with a warning (and the `--require-semantic` flag turns that skip into a
-hard failure, for maintainers who need the full gate in CI).
+The semantic layer needs `ANTHROPIC_API_KEY`. Set it as a repo Actions secret (this is
+on the onboarding checklist) so the layer runs in CI — it's the part that catches
+engagement particulars the regexes can't. Without the key it skips with a loud warning
+(the deterministic layer still hard-fails on secrets/PII), so local/offline runs work.
+**Once your key is wired, make the semantic layer mandatory** by appending
+`--require-semantic` to the gate step in `.github/workflows/sanitization.yml`: the gate
+then fails closed if the key is ever missing, instead of silently passing
+deterministic-only.
 
 To tune what counts as a particular for this domain, edit `sanitize.config.json` —
 that is the single configuration surface for the gate. See the inline comments in that
diff --git a/sanitize.config.json b/sanitize.config.json
index 5ff9790..010ee5d 100644
--- a/sanitize.config.json
+++ b/sanitize.config.json
@@ -19,6 +19,7 @@
       "personal names of subjects, clients, targets, or end-users tied to a specific engagement",
       "specific organization/company names tied to one active engagement (not generic/public reference)",
       "document IDs, file names, dataset names, account handles, or URLs specific to one engagement",
+      "a messaging or account identifier tied to a real person — a Signal/Telegram UUID, a contact phone, an allowlisted user ID (these belong in deployment config/secrets, never in the package)",
       "a codename or label that identifies one particular engagement (e.g. used as a skill name or heading)",
       "dates, locations, monetary figures, or case details that only make sense for one engagement"
     ],
diff --git a/scripts/check_sanitization.py b/scripts/check_sanitization.py
index 55213fc..ab33baa 100644
--- a/scripts/check_sanitization.py
+++ b/scripts/check_sanitization.py
@@ -59,6 +59,9 @@ def load_config(root="."):
     ("private-key-block", re.compile(r"-----BEGIN (?:RSA |EC |OPENSSH |DSA |PGP )?PRIVATE KEY-----")),
     ("email", re.compile(r"\b[A-Za-z0-9._%+\-]+@[A-Za-z0-9.\-]+\.[A-Za-z]{2,}\b")),
     ("us-phone", re.compile(r"(?<!\d)(?:\+?1[\s.\-]?)?\(?\d{3}\)?[\s.\-]\d{3}[\s.\-]\d{4}(?!\d)")),
+    # E.164 international (e.g. a contact wired into config/SOUL): "+" + 7–15 digits,
+    # no separators. The us-phone pattern only covers North-American formatting.
+    ("intl-phone", re.compile(r"(?<!\d)\+\d{7,15}(?!\d)")),
     ("ipv4", re.compile(r"(?<!\d)(?:\d{1,3}\.){3}\d{1,3}(?!\d)")),
 ]
 
diff --git a/tests/test_check_sanitization.py b/tests/test_check_sanitization.py
index 60ad929..7562edb 100644
--- a/tests/test_check_sanitization.py
+++ b/tests/test_check_sanitization.py
@@ -31,6 +31,14 @@ def test_detects_ipv4_but_allows_loopback():
     assert not any(l == "ipv4" for l, _ in cs.scan_deterministic("bind 127.0.0.1", ["127.0.0.1"]))
 
 
+def test_detects_international_phone():
+    # E.164 form with no separators — the us-phone pattern misses these entirely.
+    assert any(l == "intl-phone" for l, _ in cs.scan_deterministic("contact +442079460958 anytime", []))
+    assert any(l == "intl-phone" for l, _ in cs.scan_deterministic("MATILDE_CONTACT=+4915123456789", []))
+    # Not a phone: a short +N token (version, diff count) must not trip it.
+    assert not any(l == "intl-phone" for l, _ in cs.scan_deterministic("rebased +1234 ahead", []))
+
+
 def test_generic_methodology_is_clean():
     assert cs.scan_deterministic("Structure a handoff: decisions, threads, next step.", []) == []