AT&T SYSTEM 25 Manual page 162

Return Coverage on Busy returns to the attendant, after a specified time period, an
unanswered camped-on call. If Attendant Camp-On is not provided (that is, Camp-On
return time is administered to be zero seconds), calls released by the attendant to busy voice
terminals return to the console immediately. Calls camped onto a DGC group will return
only if the DGC group does not have a delay announcement.
The attendant can extend or camp-on a returned call again. A camped-on call not answered
within 1 to 120 seconds (administrable) after the attendant releases the call will return to the
console in one of the following ways:
On a DTAC, the call returns to the RTN-BUSY button.
On a SLAC, the call returns to a LOOP button.
On a DTAC, the RTN-BUSY button must be idle or the party remains on hold until the
button becomes available. If Send All Calls is active on a DTAC, the returning call will ring
at the console. On the SLAC, a returning camped-on call remains in the console queue until
the Attendant is idle.
DTAC
Answering a Returned Camp-On Call
1
Lift the handset.
2
Press
SLAC
Answering a Returned Camp-On Call
Lift the handset to connect to the ringing
Return Coverage on Busy
(if not selected by Ringing Line Preference).
[RTN-BUSY]
[LOOP].
Return Coverage on Busy 3-45