Panasonic KX-TDA30 Features Manual page 201

Button
Flexible CO (Trunk)
Flexible DSS (Direct Station Selection)
PF (Programmable Feature)
Conditions
• Certain buttons are equipped with a light to show line or feature status.
1.19 Proprietary Telephone (PT) Features
Used to make or receive a trunk call or can be reassigned to
a different trunk or to another feature button.
Used to access an extension with one touch. Every button is
programmed to correspond to an extension. DSS buttons can
also be reassigned to other features.
Used to access a preprogrammed feature with one touch. (no
default)
Usage
Feature Guide 201