A SOFTWARE industry group has presented an outline for a video game rating system in a move designed to pre-empt the United States' Congress from legislating its own. The rudimentary proposal, presented by the Software Publishers' Association at a consumer electronics show, is similar to Hollywood's movie rating system. ''There is a growing belief among parents that the job of limiting exposure to inappropriate information, including violent or sexually explicit materials, has become more than individual parents can manage,'' said Ken Wasch, the association's executive director. The software association represents companies that publish games for home video game machines. Several US Senators said at a December hearing that unless the industry came up with its own rating system, legislation would be introduced this year to mandate one. The association asked attendees, who included executives from software publishers, to form advisory groups that would work out details of such a system. Under the proposal, ratings would be introduced for the following categories: games suitable for all ages; games suitable for adults only; games suitable for children aged six to 13 with parental guidance; and games for those aged 13 to 17 with parental guidance. The ratings would be assigned in one of two ways. Under one option, a permanent review committee would preview all titles before they were sold to the public. The composition and method of selection of the committee remained to be decided. The other option, favoured by many at the conference, would be for software companies to submit questionnaires about the sex and violence content of video games. The questionnaires would be developed by child psychologists and parents, and publishers would be required to file affidavits with the questionnaires attesting to their accuracy. Both rating systems would be enforced by registering the ratings symbols with the US Patent and Trademark Office. The review body could rely on breach of contract and federal trademark laws to enforce the system.