AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual page 57

Introduction
MF Classification
The system's MF classification number is AS593M-72682-MF-E. This
classification is applicable to all three modes of operation—Key, Hybrid/PBX,
and Behind Switch. The system is registered under the MF classification if any
of the following conditions are met.
Key Mode of Operation
One or more ground-start trunks are connected directly to the control
unit. These trunks connect to a 400 GS/LS/TTR, 408 GS/LS, 800 GS/LS,
or 408 GS/LS-MLX module (Release 2.0 only).
Hybrid/PBX Mode of
All outside trunks are pooled; no trunks are terminated directly on a
telephone.
The only directly terminated trunks are personal lines, not shared lines—
only one telephone accesses the trunk.
Behind Switch Mode of Operation
One or more ground-start trunks are connected directly to the control
unit. These trunks connect to a 400 GS/LS/TTR, 408 GS/LS, 800 GS/LS,
or 408 GS/LS-MLX module (Release 2.0 only), The processor module
must not be strapped for Key-only operation.
PF Classification
The system's PF classification number is AS5USA-65646-PF-E. This
classification is applicable only to the Hybrid/PBX mode of operation. The
system is registered under the PF classification if either of the following
conditions is met.
Hybrid/PBX Mode of Operation
All outside trunks are pooled; no trunks are terminated directly on a
telephone.
The only directly terminated trunks are personal lines, not shared lines—
only one telephone accesses the trunk.
Operation
Modes of Operation 1-29