Panasonic KX-TG7731 Operating Instructions Manual page 48

Item
In use
Cell1 in
use
Cell2 in
use
Line in
use
*1 Corresponding cellular line(s) is indicated next to
the item.
*2 During a cellular call, the item is not displayed
even though the feature is activated.
*3 Corresponding lines (1, 2: cellular line, L:
landline) are indicated next to the item. If all
lines are turned off, no line is indicated.
Meaning
Answering system is being used by
another handset or the base unit.
Someone is using the cellular line.
Someone is using the landline.
48