8.7.3. User Interface 
- Certain rules must be met when establishing a COM Group Speaker Call:
- The station user is not busy, not off-hook, not in hands-free operation, is not in program mode.
- The telephone is not marked for voice call protection.
- The station is not restricted from terminating to that destination (e.g. ITR Internal Traffic Restriction).
- The destination cannot be an analog telephone or attendant.
- If the destination telephone does not have a microphone, the handset must be lifted to establish the two-way conversation.
- The destination extension must appear in only one node. A destination extension can be a destination in a remote node. If so, the attempted call shall be converted to a standard two party call (A-B call).
- See COM Group Call for further information.