In our era of secrecy, you can't compete with the federal government's relentless campaign to prevent you from knowing much of anything - from Guantanamo to the 9/11 attacks to the president's military record. Next to that achievement, Jack Valenti's tenure as president of the Motion Picture Association of America seems modest enough. All he did was get the government to put the thumbscrews (and the FBI) on anyone suspected of pirating Hollywood product and oversee the creation in 1968 of an MPAA-administered Voluntary Rating System to "help" parents choose films for their children.

You don't hear much about the MPAA ratings unless a film gets a rating that seems unreasonable, which is more often than you think. Just ask John Waters, Mary Harron, Kevin Smith, Jamie Babbit and Atom Egoyan about their own experiences with the ratings board. As the old cliché goes, it would be funny if it weren't so unfair.

It's still funny enough if you approach the MPAA by way of This Film Is Not Yet Rated, Kirby Dick's first-person account of his campaign to unmask the secret anonymous "parents" who hand down judgments on films, including this very documentary about the ratings system that he submits to the MPAA in the course of his story. If you ever took MPAA ratings seriously - and there must be someone out there who does, or did - you'll never take them seriously again after seeing this documentary.

After hearing laments from his fellow independents about the arbitrariness and inanity of rulings on their films, Dick walks us through a MPAA-for-Dummies, using the word "fuck" to entangle us in the logic that raters might deploy when confronted with those four fearful letters. He then hires private eyes to find out who makes these decisions. They are not your ordinary PI's, but a gentle lesbians and her daughter, Becky and Cheryl, who manage, with old-fashioned surveillance and a hidden camera bought in a "Spy Shop," to identify all of the MPAA's film raters. The once-anonymous raters stand out only in their ordinariness as they are named on-screen to the tune of perky music that could have been used for The Dating Game. Dick does get to talk on the phone to the MPAA's predictably-officious ratings chief, Joan Graves, who tells him that his doc got an NC-17 rating, due to "some graphic sexual content."

Jack Valenti is more an obvious target than an easy one. In television clips that Dick uses abundantly, Valenti comes off as a pompous, sententious little man, a veteran of advertising and politics, whom the studios liked well enough to have made him their mouthpiece for four decades. Valenti talks as if he loves the sound of his own voice. His pronouncements have the hollowness that one has come to expect of officialdom. Just wait until you hear an MPAA lawyer describe the rules of a ratings appeal hearing.