AT&T MERLIN LEGEND System Reference Manual page 84

Features
System Access
Transfer
Related Features
When an inside Auto Dial button is pressed, the system automatically selects an
Intercom or System Access button and turns on the speakerphone. When
outside Auto Dial button is pressed, the system automatically selects an outside
line button in the Key mode, a Prime Line button in the Behind Switch mode, or a
System Access button in the Hybrid/PBX mode.
Users can press Auto Dial buttons instead of dialing extension numbers to
transfer calls. To use the One-Touch Transfer option, users must program an
Auto Dial button for every extension to Which they transfer calls. When a system
operator transfers a call and it returns unanswered, the green LED next to the
Auto Dial button flashes to indicate the extension from which the call is
returning. Only system operators receive this indication.
Directory System Speed Dial
Personal Speed Dial
Auto Dial 2-35