Abstract: Television programs are broadcast to a plurality of receiver units in various geographic areas. Each unit has a memory for storage of a designation code representative of its location and a memory for the storage of a blackout tier indication. Prior to the transmission of the program to be blacked out, each unit is separately addressed and provided with a message including a designation code for storage. Then, a globally addressed message provides all receiver units having a selected designation code with a blackout tier indication for storage. A program tier indication is transmitted along with the program to be blacked out. Each unit, upon receiving the transmitted program, compares the transmitted program tier indication and the blackout tier indication in its memory. All receiver units having a stored blackout tier indication which matches the program tier indication are simultaneously prevented from displaying the program to be blacked out.

Abstract: Audio and control signals are digitized and inserted in the horizontal blanking intervals of the distributed composite television signal. The control signals are in the form of a data stream which includes a header containing group address, sync, and program-related information applicable to all receiving units, and a plurality of portions which are addressable to and contain information applicable to the control of particular individual receiving units in the addressed group. The information in the addressable portions can be altered on a real time basis such that the system operator has direct control over certain functions of individual receiving units from the transmission end.