The telephone code for call blocking is *60. Telephone subscribers can block certain unwanted numbers from calling them by using this code. Calls from a blocked caller don't make the subscriber's phone ring. Instead, the blocked caller receives a message stating his calls have been blocked.
This type of call blocking is only available with landline telephone service. When a number is blocked, the blocked caller isn't able to call the subscriber again unless the subscriber unblocks the number. Landline phone companies also often offer services such as anonymous call blocking, personalized ring, anonymous call rejection and priority ringing along with the ability to ask unidentified callers to identify themselves.