Wave Industries OLYMPIA O2400 Owner's Manual page 15

If the phone line is in use (by another telephone connected to the same line), "EXT
IN USE" is displayed. It is still possible to go off-hook during this condition.
If one handset is engaged in an external call, the message is presented in line two
of the other handset's display.
READY
EXT IN USE
In the presence of new, unplayed voicemail messages, "MESSAGE WAITING" is
displayed.
READY
MESSAGE WAITING
When there is one or more new Caller ID records in the call log, the status is
presented in line two: e.g.
READY
10 CALL/3 NEW
When the ringer is switched off, the status is presented in line two.
READY
RINGER OFF
The following messages may occur in the display during conversation.
When the battery low level is reached, the "charge battery" recommendation is
shown in line two.
TALK 1:32:56
CHARGE BATTERY
When the microphone is muted, the status is presented in line two.
TALK 1:32:56
MIC MUTE
OLYMPIA OL2400 Owner's Manual 15