Panasonic KX-TD816NZ - Manual (Page 47)

2.3 Receiving Calls
Operation
47
Customising Your Phone
• 4.1.2 Initial Settings—
Preferred Line Assignment - Incoming
Select the seized line when going off hook.
Intercom Alert Assignment
Select the Calling method, either ring or the other party's voice.
• 4.1.3 Customising the Buttons
Re-arrange the CO button and change the ringing tone for each CO button.