AT&T MERLIN Plus Training Manual page 38

To bridge into the conference call (to include one or two internal people),
each internal person should:
Action
1. Lift the handset.
Touch one of the line buttons
2.
associated with the conference
call.
To put a conference call on hold (so you can do something else while the
others continue the discussion):
Action
Touch Hold.
If you want to return to the
conference, touch either line button
associated with the conference.
32
Result
Each internal person will hear a
dial tone.
Each internal person is connected
to the conference.
Result
The conference is put on hold.
You're reconnected to the
conference.