AT&T PARTNER II Release 3.1 Programming And Use Instructions page 175

How to Join a Call
System Phone
A steady red light at a line button indicates a call is in progress at another
extension.
To join a call:
Press the line button next to the steady red light and lift the handset, or
Lift the handset and press [
number.
The red and green lights alternately flash. You are now joined with the call.
You can tell when someone has joined a call of yours when the lights next
to the line button change to alternately flashing red and green.
Standard Phone
1 . Lift the handset.
You hear intercom dial tone.
Dial [
2 .
6
If a system phone joins a call on a standard phone, there is a momentary
"break" in the call on the standard phone.
5-92
Joining Calls
] [ ] and the number of the line on which the call is being conducted.
8
] [ ] [ ] and the two-digit line
Intercom 6 8