NEC ASPILA EX Feature Manual page 114

Call Forwarding to Abbreviated Dial
100 Features
To cancel Call Forwarding Off-Premise by Door Box
1. At system phone, press idle CALL key + Dial 822.
OR
Press Call Forward (Device) key (PGM 15-07 or SC 851: 54)
OR
At DSL/SLT, lift handset and dial 822.
2. Dial 0.
3. Press SPK (or hang up at DSL/SLT) to hang up.
Your DND or Off-Premise Call Forwarding Programmable Function Key stops flashing.
Aspila EX Software Manual