AT&T MERLIN LEGEND System Reference Manual page 313

Features
Allowed Lists and
Calling Restrictions
Auto Dial
Automatic Route Selection
Callback
Call Waiting
Coverage
Direct-Line Console
Directory
Disallowed Lists
2-264 Personal Lines
A user with an outward-restricted telephone cannot dial an outside number on a
Personal Line button unless the number is on an Allowed List assigned to the
telephone. A user with a toll-restricted telephone cannot dial a toll number on a
Personal Line button unless the number is on an Allowed List assigned to the
telephone.
Only an outside Auto Dial button can be used on a personal line.
ARS cannot be used on personal lines.
The Callback feature cannot be used to request a busy personal line.
A user does not hear a Call Waiting tone for calls received on a personal line
unless the business subscribes to the Call Waiting service from the local
telephone company.
Assigning a sender as the principal user of a personal line specifies that the
calls received on the personal line are sent to the principal user's Individual and
Group receivers. A principal user with Remote Call Forwarding can forward calls
received on the personal line to an outside number.
Calls received on Personal Line buttons programmed for No Ring or on senders'
telephones other than the principal user are not eligible for Coverage.
Only one extension can be assigned as the principal user for each individual
line/trunk. If no principal user is assigned and the personal line is shared by
other senders, calls received on the personal line are sent to all available
Individual Coverage receivers for all senders sharing the line and to the Group
Coverage receivers programmed for the sender with the lowest logical ID.
Once a receiver answers a call received on a personal line on a Cover button
and puts the call on hold, the sender and any other user who shares the
personal line cannot pickup the call by pressing the Personal Line button. For
proper handling, the receiver should transfer the call to the sender.
The factory setting for all modes of analog DLCs assigns the first 1-32 lines
connected to the system as personal lines. For digital DLCs, the first 1-18 lines
connected to the system are automatically assigned as personal lines.
A System or Personal Directory (MLX-20L only) can be used to dial numbers on
a personal line. An Extension Directory is used only for inside calls and cannot
be used to dial calls on a personal line.
A user cannot select a personal line and dial an outside number when the
number is on a Disallowed List assigned to the telephone.