Note: When operated on the PBXs COMpact 3000 analogue/ISDN/VoIP, COMpact 5010 VoIP, COMpact 5020 VoIP, COMpact 4000, COMpact 5000/R, COMpact 5200/R, COMpact 5500R and COMmander 6000/R/RX: If you want to delete the callback, tap on in the redial list.