The Serial Copy Management System (SCMS) is a copy protection scheme that was created in response to the digital audio tape (DAT) invention, in order to prevent DAT recorders from making second-generation or serial copies. SCMS sets a "copy" bit in all copies, which prevents anyone from making further copies of those first copies. It does not, however, limit the number of first-generation copies made from a master.
SCMS was also included in consumer CD-R, MiniDisc and Digital Compact Cassette (DCC) players and recorders. With the demise of these formats, SCMS is not in widespread use. However, the concept of SCMS was resurrected in the broadcast flag, a measure formerly mandated by the Federal Communications Commission (FCC) to limit the copying of digital TV signals.[1] SCMS flags are also included in the MP3 specifications,[2] though no known decoder or player honors them. Personal Computers were not required to include SCMS in the US.[3]