The next time you turn on the TV, notice the small box on the upper left side of the screen. In it, one of seven codes will appear. A series of white letters might display beneath. Fifteen seconds later, the icons are gone.

The code in the box is the TV parental guidelines rating—something that’s been around for 20 years but has never really caught on with Americans. Still, even if most viewers don’t notice the boxes, millions use them unawares. That’s because streaming services like Netflix, Hulu, and Amazon Prime use the parental ratings to determine which shows to block from family profiles.

Who has the power to rate television content? WORLD took a look and discovered an opaque system where TV networks rate their own shows and sit on the board providing oversight. The result: Risqué TV-14-rated content has gradually overtaken family programming, with the Federal Communications Commission (FCC) intervening only for extreme cases of indecency.

We’ll look first at the ratings system and how it got here. Then we’ll introduce you to the TV Parental Guidelines Oversight Monitoring Board (TVOMB), a secret committee the FCC has tasked to ensure networks stick to the seven sanctioned official ratings. (TVOMB refuses to disclose the identities of its members, lists only a post office box for an address, and bars the public—including even FCC officials—from its meetings.) Then we’ll examine what parents can do.

WHAT DO THOSE SEVEN OFFICIAL RATINGS in the little box mean? The TVOMB reserves two for children’s programs (TV-Y, TV-Y7). The others roughly correspond to the well-known movie ratings system, with TV-G the equivalent of a G movie rating, TV-14 similar to PG-13, and so forth.

Or to put it more graphically: TV-G programs allow pecks on the cheek, TV-PGs passionate kisses in a park, and TV-14s allow partially clothed couples to fondle in bed. The same gradations apply for violence and language.

As to how we got to this place, you have to go back to the 1990s. Politicians wanted to appease parents upset about television’s creep toward ever more salacious programming. Technology—in the form of the V-chip—promised a way to do that. In 1996 Congress passed and Bill Clinton signed the Telecommunications Act of 1996, which mandated a voluntary TV ratings system to work in conjunction with software built into every television set (larger than 13 inches wide) produced after 2000.

Looking back, TV in the late ’90s was relatively tame—although it didn’t appear so at the time. The major networks scheduled 27 TV-G series during prime time. Contrast that with 2017, when just one TV-G show—NBC’s Little Big Shots—plays on the prime-time schedule. Meanwhile, edgier shows with coarse sexual and violent content have grown exponentially.

Twenty years ago racy TV-14 programs ran mostly in the 10 p.m. hour. Now they dominate network lineups, as broadcast television competes with cable for the viewers advertisers most want to reach. On a sample week in March, 44 of 72 programs earned a TV-14 rating. CBS’ The Big Bang Theory, one of today’s most popular TV-14 shows, airs at 8 p.m. on the East Coast.

Not all TV-14 shows are created equal. NBC, for example, assigns the rating to the family drama This Is Us. It contains mature situations parents might need to explain to kids. On the other extreme was VH1’s Dating Naked, which (until its cancellation in April) showed awkward first meetings on the beach, co-ed naked volleyball, and adults talking about each other’s genitalia.

TV watchdogs say this wide difference in the TV-14 category confuses parents, makes the system unreliable, and lets networks get away with marketing more salacious content to teens. Prime-time TV has become a desert of family programming, but TVOMB doesn’t keep track of such things: Its job is merely to ensure the uniformity and accuracy of the ratings and to respond to viewer complaints.

TVOMB keeps no historical statistics of TV ratings and does not talk about trends or content unless it relates directly to a show’s rating. Remember: Politicians were looking for a system that warned parents about objectionable content before kids began watching an episode. Nothing in the law set a quota for family-friendly programs. As the culture has coarsened, so has television.

TVOMB has a maximum of 24 members. Eighteen spots are reserved for industry insiders from broadcast and cable networks and for content producers. Up to five representatives come from public interest groups like the National PTA and Boys and Girls Clubs of America. Currently National Association of Broadcasters head Gordon Smith chairs the board and chooses the public interest representatives.

Aside from the organization names, which are listed on TVOMB’s website (tvguidelines.org), no public records show individual member names, positions, or family demographics. The four public interest groups were chosen for their devotion to children’s interests; but one is defunct, one refused to reveal the identity of its representative, and the other two declined to comment.

The last member on the list is WCOV-TV, a local Fox affiliate based in Montgomery, Ala. A representative of the station admitted he was puzzled why a “mom and pop station” like his would serve on such a board, especially when its parent organization (Fox) was already represented.

So why all the secrecy? WORLD could get only one member of the ratings board to speak on the record. Cindi Merifield said she’s fine having her name publicly associated with TVOMB. Her organization, Pause Parent Play, went defunct years ago so she doesn’t exactly represent parents anymore, but her institutional knowledge (as one of the architects behind the ratings system) probably explains why she’s still there: “It was really hard to get it signed into law. So personally I’m very proud of it. … I see no reason at all why they wouldn’t use my name.”