AT&T MERLIN LEGEND Release 2.0 Analog Direct-Line Console Operator's Manual page 57

Features
5. Press the button you labeled.
6. Dial the programming code.
Some features require additional entries. For example, you must
enter an extension for inside Auto Dial.
7. Slide the T/P switch to the center position.
To use the feature, simply press the programmed button.
4-8
Programming a Feature Button