V-chip is a technology used in television set receivers in Canada, Brazil and the United States, that allows the blocking of programs based on their ratings category. It is intended for use by parents to manage their children's television viewing based on blocking systems. Televisions manufactured for the United States market since January 2000 are required to have the V-chip technology. Since the idea for blocking programs in this way was patented and tested in Canada by Brett West and John P. Gardner in 1994, many devices using V-chip technology have been produced. V-chip technology works much like closed captioning and uses the vertical blanking interval in the television signal. The system receives a special code in the broadcast signal which indicates the show's score according to a simple numerical rating system for violence, sex, and language. The programs' signals are encoded based on their rating, on line 21 of the broadcast signal's vertical blanking interval using the XDS protocol, and this is detected by the television set's V-chip. If the program rating is outside the level configured as acceptable on that particular television, the program will be blocked. The V-chip does not block infomercial, news or sportscasts as this sort of programming does not have ratings. The V-chip has a four-digit numerical password in order to keep older children from changing its settings. However, it can be overridden by anyone who reads the television's instruction and finds out how to reset the password to 0000 (built into the V-chip in case the parents themselves forget the password that they set). The phrase "V-chip" was purportedly coined by then-Representative Ed Markey of Massachusetts. According to him the "V" stands for "violence". However, in an interview with Tim Collings, one of the people who claim to have invented the device, he said that it was intended to stand for "viewer control." History In 1975, the Family Viewing Hour was introduced in the United States, in which broadcasters had to play TV content suitable for all ages. This idea was quickly abandoned because broadcasters felt it violated their First Amendment rights by restricting what content they could play. The inventor of the V-chip technology originally meant for it to be a simple tool that parents could use to restrict their children's television viewing. He did not expect it would become a national standard for all televisions. Implementation In 1993, Keith Spicer met