AT&T MERLIN LEGEND System Reference Manual page 303

Features
Pickup
Pools
Queued Call Console
Remote Access
Station Message Detail
Recording
System Access
System Numbering
Transfer
Voice Announce to Busy
System Programming
2-254 Paging
When the line number used for loudspeaker paging is not assigned to a button
on a multiline telephone, a user can access the loudspeaker paging system by
using Individual Pickup and dialing the paging port's line number (801-880) or
by programming a Pickup button specifically for the paging port line number.
In the Hybrid/PBX mode, trunk jacks used for loudspeaker paging cannot be
assigned to trunk pools.
A QCC cannot make and receive voice-announced inside calls (speakerphone
calls to an individual extension). A QCC cannot be a member of a
speakerphone paging group. A QCC system operator can use a loudspeaker
paging system-only by selecting the feature from the display and can use Group
Page by selecting a Call button and pressing the DSS button or dialing the
extension for the group.
Loudspeaker paging cannot be accessed from outside the system via either
direct inward dialing (DID) lines or Remote Access.
Paging calls are not reported to SMDR.
Announcements using Speakerphone Paging can be made from a Shared
System Access button when a system operates in the Hybrid/PBX mode.
However, users cannot join a page, as they can other calls, on Shared System
Access buttons.
Extensions for paging groups (the factory-set extensions are 793-799) can be
renumbered.
Calls cannot be transferred to paging groups or to the loudspeaker paging
extension.
Users who program their telephones to prevent voice announcements do not
receive group speakerphone pages.
Assign telephones to paging groups.
Extensions -> More -> Group Page
Designate a loop-start (LS) or ground-start/loop-start (GS/LS) line jack as a
paging port (maximum of three).
AuxEquip -> Ldspkr Pg