Program and System Information Protocol (PSIP) is data that is transmitted along with a station's DTV signal that tells DTV receivers important information about the station and what is being broadcast. The most important function of PSIP is to provide a method for DTV receivers to identify a DTV station and to determine how a receiver can tune to it. PSIP identifies both the DTV channel and the associated NTSC (analog) channel. It helps maintain the current channel branding because DTV receivers will electronically associate the two channels making it easy for viewers to tune to the DTV station even if they do not know the channel number.
In addition to identifying the channel number, PSIP tells the receiver whether multiple program channels are being broadcast and, if so, how to find them. It identifies whether the programs are closed captioned, conveys V-chip information, if data is associated with the program, and much more. If broadcasters do not include properly encoded PSIP data in their DTV signals, receivers may not correctly identify and tune to the station. Therefore, it is vital that all broadcasters understand PSIP and include the data in their DTV stations signals. PSIP is a mandatory Advanced Television Systems Committee (ATSC) Standard