NEW YORK (CNN/Money) - Even as there is a push to toughen rules on obscenity and indecency on the nation's airwaves, the NC-17 rating is expected to be more prevalent in movie theaters than ever before.

It is still only going to be a relative trickle of the films carrying the most restrictive rating – three this year. But that is almost a flood after six years during which none of the major studios released a single NC-17 film.

The rating was created in 1990 as a replacement for the "X" rating. It was an attempt to have a rating that would prevent anyone age 17 or younger from attending a film, but not have the stigma of hard-core pornography.

But only 18 films have been released with the rating in its first 14 years, and most of those had very limited releases and domestic box office well under $1 million.

"You could say the 'NC' stands for 'No Cash,'" said Paul Dergarabedian, president of box office tracking firm Exhibitor Relations Co.

"The Dreamers" is the first major studio NC-17 release since 1997.

Independent film distributors, which unlike the major studios don't have to submit their films for ratings, generally go with an unrated release rather than an NC-17 rating.

But this year that taboo against NC-17 seems to be weakening. "The Dreamers" from Fox Searchlight pictures has already done more than $2.4 million in box office, making it the fifth-highest grossing NC-17 film of all time.

On April 16 "Young Adam" from Sony Classic Pictures is set to hit theaters, and is expected to reach 300 screens at its high point. The film stars Ewan McGregor, best known for playing Obi-Wan Kenobi in the Star Wars Episode I, II and III.

In August, Lions Gate, an independent studio, is expected to release "High Tension," a film that garnered the NC-17 rating due to violence rather than sexuality.

Executives from the studios say they don't expect any studio to make a big-budget, wide release NC-17 film in the foreseeable future, but they do think that this could be the beginning of broader use of the often-shunned rating.

"Young Adam" will carry an NC-17 rating even though only 15 seconds of cuts could have won it an R-rating.

Steve Gilula, president of distribution for Fox Searchlight, said when he started working on release plans for "The Dreamers" he found few restrictions preventing theaters from showing the NC-17 film or newspapers from accepting advertising for them.

"I had a suspicion that people were overstating the difficulty of an NC-17 release," he said. "When I went out and tested it, it really was a myth."

But Tom Bernard, co-president of Sony Classic Pictures, says he believes that a film's distribution is still hurt by the NC-17 rating.

"Imagine the anxiety of a radio station taking an ad for an NC-17 in this current environment," said Bernard. And he says that even if "The Dreamers" didn't run into restrictions at theaters, he expects "Young Adam" will because of its wider distribution plans.

"Where we'll be hindered is not in the art house screens. It's when we want to expand into multiplex theaters that have leases with their malls that say 'No NC-17.'"

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Bernard said he decided to release "Young Adam" as an NC-17 because the backlash from some critics for making cuts would have been worse than the rating. He would like to see a new rating that would keep out teens but not have the stigma of the NC-17.

"As much as people say Dreamers wasn't hurt, there was a stigma," he said. "The restrictions for NC-17 are for pornography or exploitive violence, not a movie that receives a three or four star review."

John Fithian, president of the National Association of Theater Owners say theater restrictions are rarer than Bernard believes they are – mostly at older multiplexes.

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"I think the concept that a lot of theaters won't play NC-17 is almost entirely myth," he said.

And the "hard-R" rating Bernard would like to see is really what NC-17 was designed to be, Fithian says.

"What this year is serving as is an important transition back to the use of the rating as it's suppose to be used," he said. He doesn't expect a wide-release NC-17 film anytime soon. But he said the breakthrough will come when a major director finally has the power to say no to cuts needed for an R-rating.

"Eventually, someone will make a big picture leave it NC-17 and it'll work and the debate will be over."