A network-based CLASS service of the public switched telephone network (PSTN). The feature allows the subscriber to reject all calls from callers who have blocked the display of their calling identification information (calling number and calling name). Such calls are diverted to a recorded message advising the caller that the called party does not accept anonymous calls and to unblock the caller identification information before attempting the call again. See also calling name and number blocking, CLASS, and PSTN. Cladding Normal Angle of Acceptance Critical Angle Cladding Core