Like the other networks, NBC does flash movie-theater-style letters for the overall level of the content -- most often TV-G, TV-PG, TV-14, and TV-MA for "mature audiences." By and large this is meaningless, especially when it's the producers themselves giving these ratings. And while the other networks offer parents the additional content descriptors (S, V, L or D), they're having a field day not applying them accurately to their programming.
Remember the president of ABC telling Congress they were all about "enabling their viewers to make informed choices"? A new study by the Parents Television Council, studying 638 programs and their ratings put on screen during the big "sweeps" periods in recent years, found that in the 85 shows that ABC rated PG, 52 percent of them were missing the proper content warnings. More than half the shows were wrongly evaluated. An incredible 92 percent of the shows containing sexual behavior carried no "S"; 75 percent of shows with violence contained no "V"; 60 percent of shows with racy dialogue aired no "D"; and 40 percent of the shows with curse words had no "L." So much for informed choices at ABC.
What many parents don't know is that unlike the movie system, there is no independent ratings board for television. The Kaiser Foundation folks found a majority of parents had no idea that the TV barons label themselves. The networks have a clear financial conflict of interest with an objective ratings system. If the network gives a program a tougher warning, it could scare off advertisers, lowering the network's profits. So the networks are financially motivated to underrate (or refuse to rate) their programs.
Parents are left in the lurch. There is no inter-network consistency in the ratings. There isn't even ratings consistency within each network. The TV ratings system is a perpetually broken promise, like a lemon car offered to the buyer as a souped-up sports coupe. The buyer must be wary of not just the TV product but also the broadcast TV pitchmen who pose as caring guardians of parental interests. That pose is as fictional as most of the shows these broadcasters air.