Every sport has its unspoken rules about fan behavior and fan dress – when to yell, when not to yell, what jersey is cool to wear – but does your sport have an official stand on the mankini?

Sevens rugby did actually come out against the quasi-manly form of swimwear that covers just enough (and, really, not enough). Fans at 7-a-side rugby tournaments love to dress up in wild outfits. You’ll see your superheroes, your men in chain mail, women in tutus, men in tutus, people of both gender in banana suits.

“There is nothing like being in the crowd at the USA 7s,” said fan Donn Gallon, who has been to every one. “Each year the crowd has grown, gotten more vocal and creative in their support of their teams. It is an international party with everyone ribbing each other good naturedly when their teams are competing. Crowd-watching is fun because you never know what you will see from Maori warriors, Welsh leeks, bananas, face-painted French fans in berets, bunnies decked out in the Stars and Stripes. It’s a people-watching feast.”

While the USA 7s has been in existence since 2004, it really has only been since the tournament moved to Sam Boyd Stadium in Las Vegas that the fans fully embraced the spirit of the costumery and the idea that you can and should wear anything, except a mankini.

“Strong fan support plays a huge roll and I think it definitely helps lift your game when the crowd is behind you. Kenya has a tremendous and very passionate fan base everywhere they go. Samoa and Fiji also have a pretty big support group as well,” said USA player and former Las Vegas Blackjacks star Mike Palefau.

“It is a combination of being at a sports United Nations and an American rugby Homecoming Weekend,” said longtime USA 7s fan Joseph Sommerville. “I've played since '85; all over the country and I always see someone in the stands that I haven't seen in years. It is a gathering of all the guys you've been meaning to call and the ones you've been trying to avoid. All of the international visitors are really just a cherry on top. It always great making a few new international friends and developing new locations for friendly touring."

That’s the spirit of rugby, too. Rugby fans tend to get along, even during the most tense rivalry matches. At the sevens tournament, there are fans from 15 other countries there, so getting along is pragmatic as well as the culture. But the culture rules, and love of country tinged with the right level of sportsmanship is just the done thing.

"it is one of the few rugby events held in America where you get a chance to witness rugby on the grandest scale. It is quite a site to see the global diversity of our game as 25,000 rugby-mad people cheer, sing and celebrate in unison,” enthused DC rugby fan Tal Bayer.

“I have never been to a sporting event where there were so many different nationalities,” added Tim Acker, who plays rugby for Kutztown University. “It didn't matter what team was playing, if there was a nice step or a big hit everyone would erupt. I was sitting behind Fiji for a bit last year and they were probably the loudest most intense section in the whole stadium. They didn’t have the most fans by any means, but they were loud and exciting. They have a variety of different foods outside the stadium and I think I visited about half of them. Rugby fans are unlike any other sport because it doesn't matter what team you’re cheering for.”

The players like it, too. Among the most vocal fans every year are the Kenyans.

“Not to be missed are the Kenyans,” said Gallon.

"There is something special about Las Vegas and this atmosphere is considerably heightened when you add the thunderous and wholehearted cheering of the Kenyan fan base during our play,” said Kenya star Collins Injera. “It undoubtedly puts an extra wind in our sails."

Rugby fans in America are also a special breed. They play a sport that isn’t on television a whole lot, and whose scores aren’t in their local newspaper very often. A lot of their friends don’t know what the game entails, or how much dedication it takes to be good at it.

But those players and fans truly love their game and what the game stands for – camaraderie among opponents is central to the sport, and in Las Vegas that tradition is brought to new heights.

“Every year USA 7s provides a special experience that every American rugby player should have,” said Dumont Walker. “Being surround by friends, and teammates and having the opportunity to meet new friends and future teammates is simply amazing. Without a doubt USA 7s provides the best rugby atmosphere in the United States.”

The USA 7s will be held February 10-12 at Sam Boyd Stadium in Las Vegas.

For information on tickets, go to www.usasevens.com