AT&T MERLIN LEGEND Release 3.0 Programming Summary Manual page 157

Assign Intercom or System Access Buttons
5. Each System Access Ring or Voice on an individual
assigned as a Shared System Access (SSA) button
telephones.
Release 2.1 and earlier
Each System Access Ring or Voice on an individual
assigned as a Shared System Access (SSA) button
telephones.
6.
System Access and Intercom buttons are centrally programmed and
cannot be programmed by individual telephone users.
telephone can be
on up to 27 other
telephone can be
on up to 16 other
Telephones 10-9