AT&T 7406BIS - Manual (Page 59)

Inspect
To see who’s calling 1 Press [ Inspect ]
while on a call
●
Name and number of caller are shown if from
extension; [ OUTSIDE CALL ] or other trunk source is
shown if from outside
2 Press [
Normal
] to return to display for present call
To see who’s on hold
while on a call
1 Press [ Inspect ]
2 Press [
xxxxx
] of held call
●
You remain connected to present call
To answer a new call 1 Press [
Normal
] (if not already in normal mode)
while on a call
●
Finish present call or put on hold
2 Press [ xxxxx ] of new call