AT&T MERLIN LEGEND Release 4.0 Feature Reference page 127

Feature Reference
Feature Interactions
Caller ID
Calling Restrictions
Conference
Drop
Group Calling
Recall
Speed Dial
Transfer
Beginning with Release 3.0, companies may use the 800 GS/LS-ID
module to capture calling number identification information (subscribed
to from the central office on loop-start lines only, if available). MLX
display telephones in these systems show the number of an outside call
received on a line connected to the module. However, if the customer
also subscribes to call waiting through Centrex, the number of the
waiting call is not shown on the MLX display. For more information, see
"Caller ID."
Centrex users should not be assigned calling restrictions, because the
calling restrictions should be assigned through the CO.
In Behind Switch mode, the fixed-function Conf button applies to
Centrex operation and is not recognized by the communications
system. A button can be programmed for communications system
Conference.
In Behind Switch mode, the fixed-function Drop button applies to
Centrex operation and is not recognized by the communications
system. A button can be programmed for communications system Drop.
Calls to calling groups in a system set up in Behind Switch mode follow
the communications system ring pattern, not the central office ring
pattern.
In Behind Switch mode, a Recall button should be programmed to send
switchhook flash to activate Centrex features. The system supports the
use of a Recall button only on loop-start lines.
During periods of high traffic, users may experience a delay in
obtaining dial tone from the Centrex service. This could cause
misdialing when using System Speed Dial or Personal Speed Dial.
Pause characters can be programmed as part of the Speed Dial
number after entering the access code.
In Behind Switch mode, the fixed-function Transfer button applies to
Centrex transfers and is not recognized by the communications system.
A button can be programmed for communications system Transfer.
127
Centrex Operation