WASHINGTON — The FCC is being directed to review the 22-year-old TV content ratings system to gauge its accuracy.

The review was part of the recently passed spending bill that funds the government through Sept. 30. It requires that the FCC report back to the House and Senate appropriations committee within 90 days “on the extent to which the ratings system matches the video content that is being shown and the ability of the TV Parental Guidelines Oversight Board to address public concerns.”

The ratings system went into effect in 1997, in response to pressure from parents groups and lawmakers over the proliferation of sexual and violent content on broadcast and cable TV. The labels appear briefly on screen, and include content descriptors to inform parents on what to expect in a program.

It’s designed to work in conjunction with the V-chip, a computer chip that Congress mandated to be installed in new TV sets. The ratings are overseen by a monitoring board made up of representatives from the entertainment industry and nonprofit groups.

The Parents Television Council has called for a review, as its president Tim Winter says that its research shows that it is “inaccurate, inconsistent and lacking transparency.”

“The TV content ratings system needs to be overhauled so it truly serves the needs of parents and families, and not to provide cover for an industry that is airing ever-more-explicit content at times of the day when children are likely to be watching,” he said in a statement.

A spokesman for the National Association of Broadcasters said that they had no comment. A spokesman for NCTA — The Internet & Television Association said that “we look forward to talking to the FCC about the success of the TV ratings system and how it provides parents with useful information to make informed choices about their family viewing choices.”

Hart Research Associates conducted a survey on behalf of the monitoring board last year, and it showed that 76% of parents viewed the ratings favorably.

The FCC reviewed parental control technologies in a report to Congress in 2009, and it collected comments from the public after issuing a notice of inquiry. The report noted that “a common theme that runs throughout the comments is the need for greater education and media literacy for parents and more effective diffusion of information about the tools available to them. Many commenters urge the government to play a more substantial role in meeting this need.”