10.14.1.2. User Interface 
There are different variants to park or retrieve a call:
- One access code (park code + park slot number (0-9)) is provided for
park and retrieval to/from each system park slot.
- The subscriber dials the park code followed by the system park slot number (0-9).
- If the call has been parked successfully,
- the parking subscriber receives confirmation tone,
- the used system park slot number is displayed, if the parking subscriber has a display option.
- If the requested system park slot is currently in use,
- the parking subscriber receives dial tone again,
- the parking subscriber dials the park code followed by another system park slot number (0-9) without going on-hook.
- If the call cannot be parked (e.g. all system park slots are in use), the parking subscriber receives reorder tone.
- This variant can be used by analog telephones, Keyset and DFT with/without display option.
- Optional for Keyset and DFT with display:
- To park a call to system, the subscriber uses a System Park key and the next available system park slot is selected automatically by the system and displayed.
- If the call has been parked successfully, the parking subscriber receives confirmation tone.
- If all system park slots are in use, the parking subscriber receives reorder tone.
- When idle to retrieve a parked call, the subscriber uses the System Park key and enters the system park slot number (0-9) manually.
- Optional for Keyset and DFT without display:
- To park a call to system, the subscriber uses a System Park key and enters the system park slot number (0-9) manually.
- If the call has been parked successfully, the parking subscriber receives confirmation tone.
- If the requested system park slot is currently in use,
- the parking subscriber receives dial tone again,
- the parking subscriber uses the System Park key and enters another system park slot number (0-9) without going on-hook.
- If the call cannot be parked (e.g. all system park slots are in use), the parking subscriber receives reorder tone.
- When idle to retrieve a parked call, the subscriber uses the System Park key and enters the system park slot number (0-9) manually.
- For Attendant/ACWin:
- To park a call to system, the attendant/ACWin dials the park code followed by the system park slot number (0-9). Additionally, it can use the Direct Destination Selection (DDS) key which has been programmed with the system park access code plus the system park slot number (0-9).
- If the call has been parked successfully,
- the attendant/ACWin receives confirmation tone,
- the used system park slot number is displayed.
- If the requested system park slot is currently in use but another system park slot is available, the system will place the call in the alternate system park slot and the system park slot number is displayed where the call has been parked.
- A call left on park is recalled to the parking party after a time-out of a System Park recall timer or to the Attendant/ACWin dependent upon the system parameter (COT parameter SPAH) and the state of the parking party at time-out (idle, busy or out of service).