Broadcast Flag (TV) - A Broadcast Flag is an application embedded in a digital television signal. When television broadcasts all go digital, the broadcast flags would provide technological roadblocks, thus preventing digital files from leaving the intended area. (This is a concern to content owners as viewers might want to record a program and send the recorded program to a friend.) As well as covering cable, satellite and DSL broadcasts, it’s expected to also include free over-the-air programming.
http://en.wikipedia.org/wiki/Broadcast_flag

See the Interactive Television Institute.