A:Answer According to the online owners manual;
“Flash/call waiting
If you subscribe to call waiting service with your telephone service provider, you can answer a new incoming call without losing your current call.
1. While on a call, press FLASH to connect to the new call when you receive a call waiting signal.
2. Press FLASH again to return to the original call.“
However, I don’t think it will display the incoming “call waiting “ number.