diff --git a/CHANGELOG.md b/CHANGELOG.md
index b6a41a02b..6333404d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,9 @@ All notable changes to this project are documented here. Format follows
 
 ### Fixed
 
+- The product-gap baseline now records private-runtime findings only as
+  aggregate synthetic-fixture contracts and identifies the existing
+  post-scoped lineage DAG without retaining post or organization identifiers.
 - The public ontology now states its OWL 2 Full/RDF-Based semantics for the
   ADR 0036 RDF-reified project evidence, and the PROV-O support profile uses
   its canonical lowercase deployed IRI.
diff --git a/tests/test_documentation_hygiene.py b/tests/test_documentation_hygiene.py
index 010bb5e5d..3b0f9829a 100644
--- a/tests/test_documentation_hygiene.py
+++ b/tests/test_documentation_hygiene.py
@@ -8,12 +8,19 @@
 
 _ROOT = Path(__file__).resolve().parents[1]
 _ADR_DIRECTORY = _ROOT / "docs" / "adr"
+_PRODUCT_GAP_BASELINE = _ROOT / "docs" / "product-technical-gap-baseline.md"
 _ROLE_CATALOG_COLUMNS = (
     "cataloged_team_id",
     "cataloged_corporate_entity_id",
     "cataloged_person_id",
 )
 _ADR_NAME = re.compile(r"^(?P<number>[0-9]{4})-.+\.md$")
+_PRIVATE_POST_IDENTIFIER = re.compile(
+    r"(?i)"
+    r"\b[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\b"
+    r"|\bpost(?:_id)?\s*(?:=|:)\s*[`'\"]?[a-z0-9][a-z0-9-]{5,}"
+    r"|\bpost\s+[`'\"]?(?:[0-9][a-z0-9-]{5,}|[a-f][a-f0-9-]{7,})\b"
+)
 _FORBIDDEN_MARKERS = (
     "PLACEHOLDER_DO_NOT_WRITE",
     "TODO_WRITE_ADR",
@@ -46,6 +53,23 @@ def test_adr_numbers_are_unique_and_documents_are_not_placeholders() -> None:
     assert duplicates == [], f"duplicate ADR numbers: {duplicates}"
 
 
+def test_product_gap_baseline_contains_no_private_post_identifiers() -> None:
+    """Buyer-gap evidence stays aggregate and cannot identify private runtime posts."""
+    baseline = _PRODUCT_GAP_BASELINE.read_text(encoding="utf-8")
+
+    for private_reference in (
+        "post=synthetic-12345",
+        "post: synthetic-12345",
+        "post 12345678",
+        "00000000-0000-4000-8000-000000000000",
+    ):
+        assert _PRIVATE_POST_IDENTIFIER.search(private_reference)
+    assert _PRIVATE_POST_IDENTIFIER.search("authorized post evidence remains aggregate") is None
+
+    match = _PRIVATE_POST_IDENTIFIER.search(baseline)
+    assert match is None, f"private post identifier in product-gap baseline: {match.group(0)!r}"
+
+
 def test_fetch_persisted_summary_reads_stored_catalog_ids() -> None:
     """ADR 0019 / 0027: fetch must not rejoin the catalog by a non-unique name."""