Vertical Edge 120 - Phone Lock;Unlock; Operation - Lock Your Phone; Operation - Unlock Your Phone

Edge 120 Digital Executive Telephone User Guide Page 65
Phone Lock/Unlock FEATURE 
Use this feature to prevent anyone from making unauthorized outside
line calls from your extension. This feature code is also used to
program your private, four-digit extension password.
Operation – Lock Your Phone
1. Press FEATURE .
PSWD :_
bksp show chg
2. Input the current password (factory “9999” for ext. 101, “0000” for
all others) and then press [show].
LOCK PHONE
pswd yes no
3. Press [yes].
PHONE LOCKED
4. No outside line calls can be made at this extension.
Operation – Unlock Your Phone
1. Press FEATURE .
PSWD :_
bksp show chg
2. Input the current password and then press [show].
LOCK PHONE
pswd yes no
3. Press [no].
PHONE UNLOCKED
4. Outside line calls can now be made at this extension.