NEWS ANALYSIS : What Change in Film Rating System Means : Movies: Adult-themed films can now be made and marketed without the stigma of the X.

When pornographers took the Motion Picture Assn. of America’s adults-only X rating, multiplied it by three (“XXX!!!) and made it the beacon for fans of love stories without love, they gave MPAA President Jack Valenti’s voluntary movie ratings system a flat tire. On Wednesday, after a decade of controversy, prodding and a couple of lawsuits, Valenti got out and changed the tire.

The X rating is now called NC-17. Same category, same meaning--no children under 17 admitted--but without the taint. Filmmakers can now make movies with adult themes aimed at adult audiences, and distributors will be able to market them.

“We are going back to the original intent of the rating system,” Valenti said Wednesday morning. “We have an adults-only category and anybody who wants to go see (an NC-17-rated) film can go see it, period. It takes us back to the days, hopefully, of ‘Midnight Cowboy,’ ‘Last Tango in Paris’ and ‘Clockwork Orange.’ ”

You can quibble about the time it took Valenti to repair the system that he designed and installed 22 years ago. A lot of serious adult-themed films have been butchered because distributors couldn’t book X-rated movies in theaters and because newspapers and television stations refused advertising for them. Ken Russell’s “Crimes of Passion,” Alan Parker’s “Angel Heart” and William Friedkin’s “Cruising” are just three that got caught up in public controversies; scores more were ignominiously edited down to Rs because their directors were contractually obligated to do so.

Studios can still insist on R clauses in their contracts with filmmakers, but they can no longer use the excuse that they’re necessary. The X, useful as a symbol for railroad crossings and Pussycat Theaters, is now about as relevant to the American film industry as the skull and crossbones it came to represent.

There have been two changes in the ratings system since 1968. In 1984, a firestorm of protest over the violence in Steven Spielberg’s PG-rated “Indiana Jones and the Temple of Doom” (you may recall a beating heart being ripped from a man’s chest?) forced the MPAA to come up with the PG-13. The PG-13 was more a public-relations gesture than a necessity; it merely advised parents that PG-13 films contained stronger content than those rated PG. The NC-17 does nothing less than remove a system of censorship from one of the world’s most popular art forms.

The MPAA made another adjustment in the ratings system Wednesday, and it’s a good one. From now on, the Ratings Board will provide explanations for its decisions on films that are rated R and will provide those explanations to theater owners and to most of the nation’s film critics.

Critics should provide their readers and viewers with information about the content of films, and many do. They can now use the MPAA explanations, or provide their own, or use the MPAA judgments as departure points for debate. It will all be to the benefit of parents deciding which films are appropriate for their children and--let’s face it, adults use the ratings as much for their own choices as for their kids’--the additional information will influence our viewing habits, too.

Whether the changes announced Wednesday will continue to neutralize the passions of would-be community censors remains to be seen. Certainly, the ban on advertising for X-rated films will not apply to the NC-17 rating at major newspapers and television stations; The Times and the New York Times have both published editorials calling for ratings revisions. At the same time, it is inevitable that someone will submit a film for an NC-17 rating that contains scenes repugnant to most people and blue noses will begin to twitch and itch.

But the rating system, restored to its original intent, is the right one in a free society. It is voluntary, it is easy to understand, and it does not place an arbitrary cap on how far films can go. As Valenti said Wednesday, if pornographers make a comeback in theaters (it’s almost exclusively a video business now), why would they pay the MPAA to give it an NC-17 when the X tells all?

Arguments will still arise over ratings given to specific films, and over the comparative content of films given the same ratings. Members of the Ratings Board still have to get a better sense of balance between the nature of violence and sexuality in films; critics have maintained, with plenty of evidence, that tougher standards are applied to sexuality than to mayhem.

Those arguments, however frustrating to the participants, are healthy and unavoidable in dealing with something as subjective as popular taste. To have no ratings system at all would be a disaster; Hollywood would be editing different versions of films for counties, boroughs and parishes, and for the tastes of leaders of the religious, parent or government bodies that would breed--as surely as mosquitoes in swamp water--in each of them.

Valenti made the right decision in rejecting the suggestion of some critics and directors that a new adults-only rating be inserted between the R and the X. His argument was that it would force the rating board members to decide when films were pornographic and when they were not, and he’s right. Two adults-only ratings are not necessary anyway. If children can’t get in, adults ought to be able to take care of themselves.

The immediate future of the ratings system, perhaps on the verge of collapse just two days ago, is now in the hands of theater operators. The fact that they defaulted on their promise to enforce the R rating, which originally assured parents their under-17 kids couldn’t get in without adult accompaniment, has done almost as much to cripple the system as the pornographers.

Now they are being asked, and they have agreed, to enforce an adults-only rating. That means slowing traffic at the door long enough to check IDs when NC-17 films are being shown, and--here’s the hard part--turning down admission money from those who are too young. The integrity of the system, and the newly regained freedom of filmmakers, may hang in the balance.