Block the Blocker: When you turn the service on, any callers who have blocked their number from your Caller ID display will hear an announcement that you do not accept anonymous calls – and they should remove blocking and call back.  All other calls will ring through as usual.
 
  How it Works:
1.  Lift the handset and listen for the dial tone.
2.  Press *77 (On rotary phone, dial 1177).
3.  Listen for a confirmation tone or announcement and then hang up.

To Cancel:
Press *87 (On rotary phone, dial 1187).

Listen for a confirmation tone or announcement and hang up.