AT&T MERLIN LEGEND System Reference Manual page 400

Features
Intercom or System Access
Voice Button
Intercom or System Access
Originate Only Button
In the Hybrid/PBX mode, a System Access Voice button can be used to make
and receive inside and outside calls. In the Key and Behind Switch modes, an
Intercom Voice button can be used to make inside calls only and to receive
inside calls and outside calls transferred by another user.
When an Intercom or System Access Voice button is used to make an inside
call, the person being called hears the caller's voice instead of hearing the
telephone ring, unless the person being called does not have a speakerphone
or has disabled voice announcements.
In the Hybrid/PBX mode, when a System Access Voice button is used to make
an outside call, the user selects an outside trunk by dialing either the code for
ARS or the pool dial-out code.
In the Key mode, an Intercom Voice button can be used to select a personal
line. The user dials the Idle Line Preference code (usually 9) to select an idle line
(the user cannot select a specific line/trunk).
An Intercom or System Access Voice button is automatically assigned to all
multiline telephones and MFMs connected to the system. An Intercom or System
Access Voice button is not factory-set and cannot be assigned via centralized
telephone programming to a single-line telephone or other tip/ring device
connected to a 012 or 008 OPT module.
In the Hybrid/PBX mode, a System Access Originate Only button can be used
only to make inside and outside calls. In the Key and Behind Switch modes, an
Intercom Originate Only button can be used to make inside calls only. Calls are
not received on an Intercom or System Access Originate Only button.
The purpose of the Intercom or System Access Originate Only button is to
ensure that the user always has a button available to make calls, transfer calls,
establish conference calls, answer Call Waiting calls, or pickup parked calls.
The button can be programmed for either voice or ring operation for inside calls.
In the Hybrid/PBX mode, when a System Access Originate Only button is used
to make an outside call, the user selects an outside trunk by dialing either the
code for ARS or the pool dial-out code. The System Access Originate Only
button is automatically assigned to all MFMs and multiline telephones connected
to the system, except direct-line consoles (DLCs) and QCCs.
In the Key mode, an Intercom Originate Only button can be used to select a
personal line. The user dials the Idle Line Preference code (usually 9) to select
the line.
System Access 2-351