V-chip is a generic term used for a feature of television receivers allowing the blocking of specific programs based on their content. It is intended for use by parents to control their children's television viewing. All 13-inch and larger televisions manufactured for the U.S. market since January 1, 2000 are required to have the V-chip technology.
Most television programming is given a rating based on the level of sexual, violent, or other indecent material it contains, using a TV Parental Guidelines system modeled after the Motion Picture Association of America's rating system for films. (For films airing uncut, the MPAA ratings are used.) The programs are encoded with this rating, on line 21 of the broadcast signal's vertical blanking interval, and it is detected by a television's V-chip. If the program's rating is outside the level configured as acceptable on that particular television, the program is blocked.
The V-chip technology was developed by Tim Collings , from Simon Fraser University.
The V-chip usually does not have password protection or other locking mechanism and is therefore only useful for very young children who cannot change the V-chip settings.