Vertical Comdial DX-80 User Manual page 22

Overview
3. Press F3 (OK) to enter the mode. Then press either F1 or F2 to
scroll to YES?.
4. Press F3 (OK) to confirm. The display responds as follows.
If the de-registration is successful, the LCD displays the fol-
lowing.
If the de-registration fails after about 20-30 seconds, the LCD
displays.
22
(( ))
>DE-REGISTER
(( ))
>DE-REGISTER
YES?
(( ))
DE-REGISTERING
(( ))
>DE-REGISTER