Panasonic KX-TDA30

1.3 Call Forwarding (FWD)/Do Not Disturb (DND) Features
Feature Guide 75
Feature Guide References
2.2.1 Class of Service (COS)
User Manual References
1.2.4 When the Dialled Line is Busy or There is No Answer
1.8.2 Refusing Incoming Calls (Do Not Disturb [DND])