AT&T MERLIN LEGEND System Reference Manual page 223

Features
Considerations
2-174 Forward and Follow Me
When all calls fowarded to the destination extension are to be canceled or
when the forwarding station's extension number is not known, the user dials
#*34*.
Calls forwarded to outside telephone numbers via Remote Call Forward may
vary in transmission quality.
When Remote Call Forward is used, calls are not forwarded to outside
telephone numbers on loop-start lines/trunks when the system is
programmed for unreliable disconnect for loop-start lines/trunks. The call
rings on the forwarding telephone and is not forwarded.
The capability of using Remote Call Forward to forward calls received on a
personal line (excluding loop-start lines/trunks with unreliable disconnect) to
an outside number must also be assigned in system programming and can
be assigned to only one extension for each line/trunk.
The reliable disconnect setting cannot be programmed for T1 channels that
are programmed to emulate a loop-start line/trunk. When a call is received on
a T1 channel programmed to emulate a loop-start line/trunk, and Remote Call
Forward is used, the call is forwarded to the primary system operator instead
of to the destination telephone number.
When Remote Call Forward is used and the line is shared by other users,
only the assigned principal user can forward calls to an outside number. If a
principal user is not assigned, calls cannot be forwarded to an outside
number.
When the principal user forwards calls to an outside telephone number via
Remote Call Forward, all calls received on an Intercom or System Access
button are forwarded to the outside number.
When the principal user forwards calls to an outside number via Remote Call
Forward, other users who share the personal line cannot join an in-progress
call while the outside telephone number is being dialed.
A user who shares a personal line cannot join an in-progress call forwarded
to an outside telephone number unless the user shares both the personal line
on which the call was received and the personal line used to forward the call
to the outside number.
When two or more users sharing a personal line forward calls to an extension
via Forward or Follow Me, calls received on the personal line are forwarded
to all destinations.
A user can forward calls to only one extension or outside telephone number
but can receive forwarded calls from an unlimited number of telephones.
The call cannot be forward to the destination telephone while the destination
telephone is ringing with another call. When a QCC is the destination, this
includes calls ringing in the queue until the QCC becomes available. On
multiline telephones, the call rings at the destination telephone with an
abbreviated ring, but is not forwarded. On single-line telephones, the call
rings only at the forwarding telephone.