Cheerleaders for the Carolina Panthers, known as the TopCats, must arrive at the stadium on game days at least five hours before kickoff. Body piercings and tattoos must be removed or covered. Water breaks can be taken only when the Panthers are on offense. TopCats must leave the stadium to change into their personal attire.

Baltimore Ravens cheerleaders were subject to regular weigh-ins and are expected to “maintain ideal body weight,” according to a handbook from 2009. The Cincinnati Ben-Gals were even more precise in recent years: Cheerleaders had to be within three pounds of their “ideal weight.”

Some cheerleaders must pay hundreds of dollars for their uniforms, yet are paid little more than minimum wage. Cheerleaders must sell raffle tickets and calendars and appear at charity events and golf tournaments, yet they receive none of the proceeds. Cheerleader handbooks, seven of which have been reviewed by The New York Times, include personal hygiene tips, like shaving techniques and the proper use of tampons. In some cases, wearing sweatpants in public is forbidden.

The New Orleans Saints, who fired a cheerleader this year for posting a picture the team deemed inappropriate on her private Instagram account, are one of many National Football League teams with stringent, and seemingly anachronistic, rules for their cheerleaders.

Across the N.F.L., teams even try to place extensive controls on how cheerleaders conduct their lives outside work. This includes limiting their social media activity as well as the people they choose to date and socialize with. Restrictions are placed on their nail polish and jewelry.

Those rules and additional work requirements have fueled another public relations headache for the N.F.L., after The Times revealed last week that Bailey Davis, the cheerleader the Saints dismissed in January, filed a complaint with the Equal Employment Opportunity Commission claiming unfair treatment. The complaint comes at time when the N.F.L. is dealing with issues of domestic violence and sexual harassment among players and league employees, and when issues of gender equality are facing unprecedented scrutiny in nearly every corner of the country.

The complaint is the first step in what could be a lengthy litigation with the Saints franchise and the league. Ms. Davis spent much of last week appearing on television, criticizing the Saints and other N.F.L. teams for having rules that she said demean women.

Leslie A. Lanusse, a lawyer representing the Saints, said the franchise strives to treat all employees fairly and denied that the franchise had discriminated against Ms. Davis because of her gender. “At the appropriate time and in the appropriate forum, the Saints will defend the organization’s policies and workplace rules,” Ms. Lanusse said in an email.

The N.F.L. declined to comment. The Ravens did not respond to questions about their current policies. The Bengals said they had updated their rules for cheerleaders and no longer have precise weight guidelines.

Unlike N.F.L. players, who are unionized and generally free to promote themselves in any way they choose, cheerleaders are part-time workers with few benefits. A few teams, including the Chicago Bears, the Giants and the Pittsburgh Steelers, do not employ cheerleaders. Most of the more than two dozen other teams with cheerleaders outline the rules and restrictions in the cheerleaders’ contracts and handbooks.

Other rules are applied as a specific reaction to an ever-changing social environment. Cheerleaders who complain about the conditions are told that they can easily be replaced. The threats are not empty. In this employee-employer relationship, the teams have all the leverage.

“The club’s intention is to completely control the behavior of the women, even when they are not actually at their workplace,” said Leslie Levy, who represented cheerleaders who sued the Jets and the Oakland Raiders. “It’s an issue of power. You see a disparate treatment between the cheerleaders, and the mascots and anyone else who works for the team. I can’t think of another arena where employers exert this level of control, even when they are not at work.”

Ms. Levy and other lawyers have had some success. In 2016 the Jets agreed to pay their cheerleaders, known as The Flight Crew, almost $325,000 in back pay. The Raiders agreed to $1.25 million in back pay for the Raiderettes. (The Raiders did not respond to questions about their cheerleading policies.)

Despite increases in pay, the rules persist in part because supply outweighs demand. Most teams employ only a few dozen cheerleaders, who must audition along with hundreds of other candidates every year to keep their jobs. In the case of the Saints, cheerleaders are limited to a maximum of four years with the club. Yet thousands of women are eager to join the squad.

To be sure, there are cheerleaders for whom the good experiences far outweigh the bad.

“Cheerleading changed my life,” said Flavia Berys, a former cheerleader for the San Diego Chargers who wrote books on audition secrets and became a real estate lawyer. “When I was an N.F.L. cheerleader, I learned a lot about how to speak to the media, I learned about the rules of decorum and professionalism. We were taught how to interact with the staff and the players, and everything. The training we had was all for a reason, and looking back, I think it was all for the right reasons.”

Nearly every N.F.L. team owner is a man, though some cheerleader programs are run by female executives. The league lets the teams establish their own rules for cheerleading squads.

Cheerleaders are seen as an integral part of the game-day experience, well-established entertainment that fans and television networks have come to expect at sports stadiums. For decades, many teams have subscribed to the philosophy that sex sells, so cheerleaders’ dress in skimpy outfits, wave pompoms and dance suggestively throughout football games, where the majority of fans are men.

But for all their upbeat energy on game days, cheerleaders toil under intense scrutiny, based on the rules included in the handbooks issued by nearly a dozen N.F.L. teams, as well as many of the unwritten rules of the job.

For several years, the cheerleaders for the Saints, the Saintsations, had to sell glossy calendars of themselves in bikinis. Before each home game, cheerleaders walked outside the stadium and tried to sell their allotment of 20 calendars to fans, many of whom had been drinking. If they failed to sell all 20, the cheerleaders had to wander the stands between quarters.

“You walk by a guy and you’re afraid you’re going to get touched,” said Ms. Davis, the former member of the Saintsations fired in January for the Instagram post. “Every girl dreads going out there before the games. We didn’t feel very important because we were literally thrown into the mix with the fans. Who would throw professional cheerleaders, walking around with cash, out with drunk fans?”

Before the Buffalo Bills’ cheerleaders, known as the Jills, were disbanded several years ago following a lawsuit, dancers were expected to sell 50 calendars a season. They had to buy them in advance, for $10, and sell them for $15. They were allowed to pocket the profit.

Like most teams, the Ravens prohibit cheerleaders from working for other teams, or from taking part in exotic dancing, posing nude or seminude, or “performing in tasteless films, photos or bikini/swimwear contest.”

The handbook given to the Oakland Raiderettes included a list of fines. Cheerleaders must pay $10 if they bring the wrong pompoms to practice, or their boots are not polished on game day. If they forgot all or part of their uniform on game day, they could be docked an entire day’s pay. The Raiderettes — known as Football’s Fabulous Females — are also coached on their body language and dining etiquette. (“Bread is to be broken with your hands” and “pass food to your right.”)

Even when they aren’t on duty for their teams, cheerleaders are subject to specific franchise rules about their behavior. They are forbidden from fraternizing with players. They cannot speak with them, seek their autographs or follow them on social media. They must block players who follow them. They are not allowed to post pictures of themselves in uniform. Teams say this rule is to prevent the cheerleaders from attracting stalkers.

According to their 2016 handbook, the San Francisco Gold Rush cheerleaders are told never to disclose that they are affiliated with the team. They are also advised to “turn off your GPS applications on your phone that will indicate where you are any given time.”

Some teams are adapting. The Los Angeles Rams recently announced that for the first time, two men will join their team of 40 dancers. (Men have worked as acrobats and baton twirlers on N.F.L. sidelines before.) Keely Fimbres, the head of cheerleading for the Rams for 28 years, said adding men to the team is a sign that gender roles are changing, however slowly.

“I think this is just the right timing because we talk about equality and inclusiveness,” she said. “They’ll be fun to watch on Sundays.”