War can be hell on public television. It just can't contain any "fucks" or "shits" before 10 p.m.

Scenes of war on PBS in which soldiers use profanity have been cut or elaborately avoided in two upcoming Frontline documentaries. According to the journalists and PBS executives responsible, these edits have been made for one reason: fear of the Federal Communications Commission.

On Oct. 3, at 9 p.m., PBS will air Return of the Taliban. Its producer and writer, Martin Smith, is now sanitizing a sequence of the documentary.

"Some Canadian soldiers are fighting," Mr. Smith said. "They're in combat, and they're going, ‘Fuck!'"

After consultation with PBS executives and lawyers, Mr. Smith decided the scene is not worth "going to the mat for." Either he'll bleep the "fuck," or scrub the scene altogether, before the film airs.

"It's a really sorry state of affairs if we're Disney-fying combat," Mr. Smith said.

Return of the Taliban will be the 36th hour Frontline has devoted to terrorism and the Middle East since 2001. But it's the struggle at home, the one with the F.C.C., that is exacting a high cost from PBS.

"What I fear, really, is that we're on the verge of making some of our best material less forceful, less powerful," said Louis Wiley Jr., the executive editor of Frontline. "You get into a situation where we're all going to be looking not to what is the best choice editorially for what we publish, but what is this government agency going to do to us? They get us to do the censorship ourselves. They use a huge cudgel. They threaten everyone with these draconian fines, and they don't have to do anything. It accomplishes the same end."

"When we're dealing with combat situations, we're always going to be in the place where we're going to come up against this," said David Fanning, the executive producer of Frontline.

Ken Burns is putting the finishing touches on The War, his epic film about World War II. It will air in September 2007. Over its 15 hours, a few veterans "employ language that, we say, they would not have used back home with their families," Mr. Burns said.

"It is very important that we as a free country don't become what we despise in an age of such palpable threats," Mr. Burns said. "There's always a tendency that in trying to eradicate evil in the world, we sometimes come to resemble the thing we're trying to eradicate."

In March of this year, the F.C.C. declared that "shit" had an "inherently excretory connotation" and therefore could no longer be used before 10 p.m. (10 p.m. to 6 a.m. was declared in the mid-90's by a series of court decisions to be a "safe harbor" for adult material and language.) "Fuck" has been indecent to the F.C.C. since 2004, after Nobel Peace Prize nominee Bono issued the expletive at the 2003 Golden Globes.

On March 15, the PBS affiliate in San Mateo, Calif.—run by the local community college—was fined $15,000 for having rebroadcast The Blues: Godfathers and Sons two years previous. More than 150,000 Californians watched; at least one viewer complained about the language, which included several variations on "fuck" and "shit" spoken by blues musicians, using an online form accessible through the Parents Television Council Web site.

PBS considered itself warned.

On June 15, not long after "shit" made the F.C.C.'s list, President Bush signed a bill increasing the maximum fine for an indecency violation tenfold. Now a single utterance of either word, whether from soldier, spy or bluesman, can mean a $325,000 penalty—an amount greater than the annual government funding for some small PBS affiliates.

Over this summer, the PBS legal department instituted a rule requiring producers to pixilate the mouths of people who were uttering words deemed indecent. Three months later, the rule, which went well beyond even the F.C.C.'s requirements, was abandoned.

But the problem of language remains.

Pulitzer Prize winner Lowell Bergman's PBS doc The Enemy Within—it investigates domestic terrorism cases regarded as victories by Homeland Security—will air on Oct. 10. In one case, involving a suspect in Lodi, Calif., Mr. Bergman used an audiotape "in which the government informant uses various obscenities in talking to the target, an unemployed, 19-year-old, sixth-grade dropout, and we can't quote them on air," he said.

"You're fucking lazy, get off your ass, get the fuck in there," Mr. Bergman said were among the things the informant said. "I can't quote the informant on TV, so I had to stop and explain the F.C.C. policy in the middle of the interview."

Some of the politics are global, as with the war. Some are personal. While PBS producers have trimmed obscenities from Frontline documentaries on the Iraq war and the treatment of the mentally ill, they have also wondered whether to pixilate Helen Mirren's mouth as she shouts an inaudible "fuck" from the driver's seat of a car on Masterpiece Theatre. They have questioned whether to black-box Marilyn Monroe's naked body as it appears on Antiques Roadshow in an old photograph. (Its value? $20,000.)

Earlier this fall, producers removed a shot of sexually suggestive 18th-century engravings from a documentary about Marie Antoinette. That was not enough. According to the Denver Post, Rocky Mountain PBS, and other affiliates, refused to carry the documentary this week. Some will air the show at a later date—and time.

PBS performed a clever decency jujitsu on a six-hour Frontline documentary called "Country Boys," about two Kentucky teenagers who occasionally employed salty language. The program aired for three nights between 9 and 11 p.m. In the first hour, the boys mysteriously didn't swear. In the second hour, within the "safe harbor" indemnity, they did.

Michael Kirk, a PBS journalist, is revising part of his back catalog to make it palatable for today's audiences. In 2002, he cut two versions of a documentary called American Porn. Seven stations chose not to air even the cleaner version. The lawyers were in the editing room. "It was a scream," he said. "They were saying, ‘No, you can see too much of the breast.' And I was saying, ‘Come on! It's a film about porn! People are going to know what's behind the blur.'"

That film "will never see the light of day again," Mr. Kirk said.

PBS may have more at stake financially, but the broadcast networks, with their deeper pockets, have drawn the heaviest indecency fines. They have banded together to fight the policy in court. In early September, a Manhattan federal appeals court gave the F.C.C. 60 days to reconsider its profanity policy. That put a temporary halt to the enforcement of more recent rulings, including for language on a repeat of NYPD Blue and a Survivor reject's description of a former fellow castaway as a "bullshitter" on an episode of CBS's The Early Show.

"One thing that worries me about this," said Martin Franks, executive vice president of CBS, "is what if the next Norman Lear has the next All in the Family in his or her word processor at the moment? Are they deciding not to take it to a network because they think that the atmosphere isn't right for it? You go back and look at the real pilot, not an edited version, of All in the Family, and in this atmosphere, it's an interesting question as to whether or not it would make it on the air. And yet, there's a show that helped change our society."

But PBS is different from the networks, in more than one way. It is one of the few television outlets doing serious journalism about the war, or wars.

"We're not talking about Hustler magazine on television," said John Wilson, senior vice president of programming services for PBS. "This is not the coarsening of culture that the commissioners were worried about and trying to regulate."

A major organizing force behind F.C.C. complaints contends that war documentaries are unintended victims—just dolphins in the tuna nets.

"Clearly those are not the type of things that are meant to be addressed by this law," said Dan Isett, the director of corporate and government affairs for the Parents Television Council. "However, they could simply avoid the whole discussion by waiting until after 10 o'clock to air these things. If you're running a documentary about the war, who is the audience going to be? The audience is adults."

And anyway, Mr. Isett said, "much of this is ado about nothing. Much of this is just hand-wringing about the so-called chilling effect of indecency law."

But how much will it cost the network to air, for example, footage of one soldier with post-traumatic stress disorder remembering when his commanding officer called him a "fucking pussy" for not fighting? Nothing, yet. PBS bleeped out the "fucking" and left in the "pussy." One viewer complained immediately. The F.C.C. is investigating.

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