diff --git a/docs/CORE_2_DRAFT_4_POST_TAG_NOTE.md b/docs/CORE_2_DRAFT_4_POST_TAG_NOTE.md
new file mode 100644
index 0000000..7ee11ac
--- /dev/null
+++ b/docs/CORE_2_DRAFT_4_POST_TAG_NOTE.md
@@ -0,0 +1,45 @@
+# Core 2.0 Draft 4 Post-Tag Note
+
+Status
+------
+
+- Tag: `v2.0.0-draft.4`
+- Stability: draft / pre-release / not stable
+- Note type: post-tag review-fix note
+- Tag policy: Do not move or recreate the `v2.0.0-draft.4` tag.
+
+Summary
+-------
+
+- `v2.0.0-draft.4` was tagged as a post-draft.3 runner hardening milestone.
+- After tagging, a review found that `report_expected_basic.json` was still stale at 10 cases.
+- A follow-up PR updated the fixture to the current 11-case conformance pack.
+- A semantic regression assertion was added so the fixture does not drift again.
+
+Current main after fix
+----------------------
+
+- Official conformance pack remains 11 cases.
+- Expected conformance output remains total=11 passed=11 failed=0.
+- Public JSON report shape remains unchanged.
+- `report_version` remains `core-2-conformance-report-v1`.
+- `v1.0.0` remains stable/latest.
+
+Release note suggestion
+-----------------------
+
+- The GitHub release notes for `v2.0.0-draft.4` may mention that main now includes a post-tag fixture consistency fix.
+- Do not retag `v2.0.0-draft.4`.
+- Use main for the latest post-draft.4 review-fix state.
+
+Validation
+----------
+
+- `go test ./...` passes.
+- Experimental conformance CLI reports total=11 passed=11 failed=0.
+- Experimental conformance CLI `--json` reports status PASS, total 11, passed 11, failed 0.
+
+Compatibility statement
+-----------------------
+
+This post-tag note does not move, recreate, or replace `v2.0.0-draft.4`. Core 2.0 remains draft and pre-release, the public JSON report shape remains unchanged, and `v1.0.0` remains the stable/latest line.
diff --git a/docs/CORE_2_DRAFT_4_READINESS.md b/docs/CORE_2_DRAFT_4_READINESS.md
index 8d6cdd7..d9f67fe 100644
--- a/docs/CORE_2_DRAFT_4_READINESS.md
+++ b/docs/CORE_2_DRAFT_4_READINESS.md
@@ -58,6 +58,13 @@ Before tagging Draft 4
 - Confirm v1.0 behavior remains unchanged
 - Confirm no unexpected files are modified
 
+Post-tag review-fix note
+------------------------
+
+- After `v2.0.0-draft.4` was tagged, a follow-up review-fix on main updated the basic conformance report fixture to the current 11-case pack and added a semantic regression assertion.
+- See `docs/CORE_2_DRAFT_4_POST_TAG_NOTE.md`.
+- Do not move or recreate the `v2.0.0-draft.4` tag.
+
 Proposed tag
 ------------
 
diff --git a/docs/CORE_2_STATUS.md b/docs/CORE_2_STATUS.md
index 3703f2f..4fa4f5b 100644
--- a/docs/CORE_2_STATUS.md
+++ b/docs/CORE_2_STATUS.md
@@ -140,6 +140,10 @@ This document summarizes the current hardening status for DigiEmu Core 2.0: what
 	future `v2.0.0-draft.4` milestone without tagging it and records the current
 	11-case conformance status (`total=11 passed=11 failed=0`).
 
+- Draft 4 post-tag note: `docs/CORE_2_DRAFT_4_POST_TAG_NOTE.md` records that
+	main includes a post-`v2.0.0-draft.4` review-fix for the basic conformance
+	report fixture without moving or recreating the draft tag.
+
 ## Known Risks
 
 - Verify Result v2 remains draft and is not yet active CLI behavior.
diff --git a/docs/SPEC_INDEX_v1.0.md b/docs/SPEC_INDEX_v1.0.md
index 7b37cb4..5f27ca1 100644
--- a/docs/SPEC_INDEX_v1.0.md
+++ b/docs/SPEC_INDEX_v1.0.md
@@ -100,6 +100,7 @@ These documents are forward-compatible Core 2.0 hardening drafts and do not repl
  - `docs/CORE_2_DRAFT_2_REVIEW_SUMMARY.md`
  - `docs/CORE_2_DRAFT_3_READINESS.md`
  - `docs/CORE_2_DRAFT_4_READINESS.md`
+ - `docs/CORE_2_DRAFT_4_POST_TAG_NOTE.md`
  - `docs/CORE_2_POST_DRAFT_3_HARDENING_SUMMARY.md`
  - `docs/CORE_2_MISSING_REFERENCE_SCHEMA_CONSIDERATION.md`
  - `docs/CORE_2_RELEASE_NOTES_DRAFT.md`