Desk phones can now use supervision keys to park and retrieve calls directly from Call Park slots. Administrators and users can assign keys to slots 1 to 9. When a slot is free, the key parks the active call. When the slot is busy, the same key retrieves it. The key also displays the slot status and automatically triggers the blind transfer required for park and unpark actions. Supported on Mx, Mx-S, H3G, and ALE-2 devices.