## CR 26.517 CR#0038 – OpenAPI YAML Corrections (5MBP3)

**Source:** BBC | **Meeting:** SA4#135bis-e | **Category:** A (mirror) | **Release:** Rel-18

### Summary

- **Problem:** The `cancelled` property defined in the normative TS 26.517 specification for `ServiceScheduleDescription` was missing from the OpenAPI YAML schema in Annex A.2.1 (`TS26517_MBSUserServiceAnnouncement.yaml`).
- **Impact:** Without this property, cancellation of MBS User Service Announcements is not possible via the API.
- **Fix:** Adds the missing `cancelled` boolean property (default: `false`) to the `ServiceScheduleDescription` schema object in the YAML.
- **Additional housekeeping:** Copyright year updated (2024→2026), spec version reference updated in `externalDocs` (V18.3→V18.6.0), and YAML `version` field bumped to `2.1.01`.
- **Affected clause:** A.2.1 of TR 26.517 (MBS User Service Announcement schema).
- **No other specs affected** (test specs, O&M, other core specs not impacted).