Ericsson DT288 User Manual page 122

The lists below explains the use of the buttons and keys on the cordless
phone.
Key
V O L U M E U P
and
V O L U M E D O W N
YES
CLR
/ /
NO
O N O F F
and
Function
Earpiece volume louder/quieter.
Make a call or answer a call.
Confirm a menu option.
During call: microphone off.
While entering text or a number: delete last letter or digit, delete
whole line if held longer.
If the cordless phone rings: mute sound. In stand-by mode mute
ringer and warning sound permanently.
Cancel a menu option, cordless phone goes on stand-by.
If held for 1 second: switch cordless phone on.
If held for 1 second during stand-by: switch cordless phone off.
If the cordless phone rings: mute sound.
End a call.
Cancel a menu option.
Start menu.
Scroll through menu options or lists.
While entering text or number: move one character position, move
to end or beginning if held longer.
Reference 122