AT&T Merlin Legend 10BS User Manual page 168

Features
Handling an Unsuccessful Transfer
An unsuccessful transfer results when the extension you are
calling is busy or unanswered. You can either return to the
held call and take a message, or continue trying to connect
the call by using one of the following features:
Camp-On puts the transferred call on hold for a preset
time. (If the call is unanswered, it rings back at your
phone.)
Paging allows you to broadcast an announcement over
co-workers' speakerphones or over a loudspeaker
system.
Park and Paging allow you to put a call on hold and
page a co-worker to pick up the call from another
phone.
Transfer 5-91