Blocking Programs

V-Chip Technology

The V-chip is a technology that allows television users to block out programming based on a rating system. While “V-chip” technically refers to a specific patented technology, the word has also come to be used as a generic term to describe any type of television blocking feature.

Invention of the V-chip is generally credited to Tim Collings while he was an engineering professor at Simon Fraser University in British Columbia, Canada. Other individuals, however, also claim to have invented similar technology. The “V” is widely thought to stand for “violence”, but Collings states that it actually stands for “viewer control”.

With the actual V-chip in an analog television set, a program’s rating is encoded on line 21 of the vertical blanking interval. This electronic information is invisible to viewers, but it can be detected by the television set’s V-chip. Using an on-screen menu, viewers select what level of programming they want to block.

With digital television, the rating information is transmitted using what is called the Program and System Information Protocol (PSIP). The PSIP also contains other digital information about the program, such as broadcast time and program description, some of which can appear on the on-screen menu. The V-chip settings in a digital television set will only work if the broadcast signals are received via over-the-air broadcasting or digital cable. The rating information cannot be passed through component video or HDMI connections. Like analog sets, viewers use an on-screen V-chip menu to select what level of programming they want to block.

How It Works

The process begins with the broadcasters. Broadcasters must choose the appropriate rating for each program and encode that information into the broadcast signal. A rating icon appears in the upper left-hand corner of the screen at the beginning of the program. The rating is based on the amount and nature of the violence, coarse language, sexuality and/or other mature themes in the program. Note that not all types of programs have to be rated; most information and non-fiction programming is exempt from classification.

Most analog television sets with a screen size of over 13 inches made for the Canadian market since 2001 and most digital sets made for the North American market since 2006 have some form of V-chip technology built in. Most, but not necessarily all, will be compatible with the Canadian rating systems. Inclusion of the Canadian classification systems in television sets is not a regulatory or legislative requirement, but most manufacturers do include them on a voluntary basis.

Using the television set’s on-screen menu, users can set the level of programming they wish to block. For example, if a user selects a PG rating, all programs at that level and below are allowed to pass through the V-chip and be viewed. Any programs with a rating above that level will be blocked and the screen will go blank.

Some televisions allow you to set different levels for each of the English Canadian, French Canadian and American ratings systems.

Users select a passcode number in order to set the blocking levels. The settings can only be changed or deactivated by using this passcode number, which helps to ensure parental control over children’s viewing.

The appearance and location of the on-screen menu, as well as the precise steps required to block programs differ between television sets. Users should consult their television manuals to find out how to use the V-chip in their specific television sets.

In addition, many cable and satellite television providers offer their own blocking technology which work with their decoder boxes. There is no requirement for satellite or cable distributors to use any particular classification system, so they may use rating categories that are different from those established for Canadian broadcasters by the Action Group on Violence On Television (AGVOT). Viewers who subscribe to cable or satellite television service should contact their providers for information on how to block programs using those individual technologies.