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
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