AT&T MERLIN LEGEND Release 3.0 Programming Summary Manual page 149

Telephones
This section contains the following summaries:
Assigning outside lines or trunks to the buttons on a telephone
(including lines and trunks used for loudspeaker paging).
Copying line button assignments from one telephone to an individual
telephone or block of telephones.
Assigning the following buttons on telephones (for Hybrid/PBX
systems only):
— System Access or Intercom Voice
— System Access or Intercom Ring
— System Access or Intercom Originate Only
— Shared System or Intercom Access
Identifying analog multiline telephones that do not have built-in
speakerphones (BIS) or Hands Free Answer on Intercom (HFAI)
capability.
Identifying analog multiline telephones that require pairing of extension
jacks to provide the Voice Announce to Busy, or to provide voice and
data features.
10
Telephones 10-1