When you receive an incoming call your telephone will identify the number of the caller. The majority of phones also identify the name of the caller if he/she has been entered into the phone’s contact list.
The number will not be identified if subscriber calling you has "Block number identification" service enabled.
To enable dial USSD-command: *0809*2*3*1#
To disable dial USSD-command: *0809*2*3*0#