diff --git a/Crewing-Implementation-Spec.md b/Crewing-Implementation-Spec.md
index e11a9d4..474fd20 100644
--- a/Crewing-Implementation-Spec.md
+++ b/Crewing-Implementation-Spec.md
@@ -415,9 +415,12 @@ with these reconciliations:
 > Onboarding promotes the candidate to `EMPLOYEE` with a `CRW-` number; **SITE_STAFF
 > login creation for management ranks (`grantsLogin`) is a deferred follow-up**.
 >
-> **Phase 4** is in progress as stacked sub-PRs: **4a Crew records & profile + PPE
+> **Phase 4 ✅ complete** — stacked sub-PRs: **4a Crew records & profile + PPE
 > (Epics E, F) ✅**, **4b Leave & attendance (Epic G) ✅**, **4c Sign-off &
-> experience (Epic K) — pending**. 4a applies role-based PII masking server-side
+> experience (Epic K) ✅**. Sign-off ends a tour (`SIGNED_OFF`), appends an internal
+> `EXPERIENCE_RECORD`, flips the **same `CrewMember`** `EMPLOYEE → EX_HAND` (returns
+> to Candidates), and auto-raises a `SIGN_OFF` backfill — the reverse of
+> onboarding/placement on one row. 4a applies role-based PII masking server-side
 > (bank/Aadhaar full only for Accounts; salary hidden from site staff, §6/§8.8).
 > Deferrals carried in 4a: site-staff own-site scoping (needs a User↔Site link),
 > the records **verify queue** (§8.11 → Phase 5), and the Pay-status tab beyond the