One particular chant, though innocent, sounds like a two-word expletive.
"Believe me, I'm no prude, but I'm a little surprised," said Ken Rudnick, a fan who lives in Deptford. "I wonder if management has sat down with them."
Mike Naioti, vice president of the 5,200-member Sons of Ben, said the group has worked with the team to tone down some chants, although "the language we use is no different than in the majority of all the stadiums in the league."
"We've tried to compromise," Naioti said. "But we're not going to give up the uniqueness and the atmosphere we do provide."
The 2,000-seat Supporters Section, known as the River End, was built to be the place where the most rabid fans could howl. And, boy, do they - standing, banging drums, waving flags, clapping, and cheering for the entire 90-minute match. The Sons' enthusiasm drives the energy at the 18,500-seat stadium.
Some new SOB traditions are sweet, such as singing the group theme song, "I'm Looking Over a Four Leaf Clover," at the 20 minute, 10 second point of every match. That's 20:10 as in 2010, the year of this inaugural season.
It's other ditties that have people talking.
For most of the season, when an opposing player took a goal kick, the Sons called out, "You suck (expletive)!" They shout "Sucks!" after each visiting player is introduced, which strikes some as not just rude but also cliché.
The chant that draws the most attention, and that irks parents who attend games with children, is one where the Sons aren't saying what it sounds like they're saying.
Naioti said he couldn't understand the complaints - until he watched a game on TV and realized that, from a distance, the phrase indeed sounded like a two-word curse that rhymes with "Le Toux."
It has left some fans disbelieving. "Are they really saying that?" one fan who doesn't often attend games asked at Saturday's match.
In fact, the Sons are shouting, "C'mon the U!"
"We're trying to educate the rest of the fans in the stadium as to what we're saying," Naioti said. "Not to say we're indifferent, but there hasn't been a real push to change it yet."
Union president Tom Veit said that in gathering feedback from fans, language has been an issue. Team officials are working with the SOB on solutions and have taken steps on their own: The Union posted the lyrics to the songs and chants on the team website. When the "C'mon the U!" chant begins, the team flashes the words on electronic stadium signs.
"I don't think anybody realized the impact that 2,000 people can have on a stadium," Veit said. "We're never going to take away the spirit of that section, but we want somebody sitting in the next section to be comfortable."
Sons of Ben president Bryan James said the team and its supporters group are undergoing a learning process on what should and shouldn't be said.
"We've had complaints - and areas of improvement," James said. "From my perspective, I think it's a lot of people who are making a big deal out of not much."
The goal-kick chant has all but disappeared, he noted. It was heard only once at Saturday's game against Chivas USA.
It's frustrating, James said, because there's nothing heard at a Union game that goes unspoken at Eagles or Phillies contests. It's particularly hard when the Sons are blamed for language they didn't actually use.
"Because it's 2,000 people chanting one word in unison, it's moral Armageddon," James said.
The $122 million stadium stands on the Chester waterfront, in the shadow of the Commodore Barry Bridge. Before the start of the season, Union executives predicted every game would sell out. That hasn't happened. But no one in charge is complaining.
While some established MLS clubs struggle to draw 10,000 a game, the first-year Union ranks fourth among 16 teams in attendance, with an average of 19,611.
That figure is boosted by crowds of 34,870 and 25,038 that attended the first two home games, played at Lincoln Financial Field while PPL Park was being built. At the new stadium, the team has averaged 17,543 during 10 league games.
That's 95 percent of stadium capacity.
The Union has three home games left.
Team officials want PPL Park to be used for more than Union games. College soccer teams play some games there, and big high school games are a possibility. The venue was constructed with a built-in stage, and rock concerts are expected to be scheduled. The NCAA men's lacrosse quarterfinals will be at PPL Park in 2012 - and by then the stadium will doubtless have undergone changes.
"You get into a stadium, and you tweak it," said stadium general manager Mike Scanlon, who has run pro basketball and hockey arenas. "You learn a lot of things when the customers actually use it."
Union officials said all along that moving into the stadium would be like slipping into new shoes: You never truly know how they'll feel until you're in them.
"I think we got a great pair of shoes that are breaking in better than we expected," said team CEO Nick Sakiewicz. "That doesn't mean there haven't been issues and challenges."
Team officials promised that parking would be a yearlong work in progress, and they weren't kidding. For instance, Lot A, north of the bridge, has one way in and one way out, making bottlenecks common. Still, the team says, all lots empty within an hour of game's end.
Bill Ewing, a fan from Philadelphia, skips the parking battle, taking a SEPTA train to Chester and then catching a team shuttle to PPL Park. "Easy, convenient, and well-done," he said.
Inside, workers are invariably friendly, whether they're handing out programs or serving food. Offerings include Crabfries at Chickie's & Pete's and specialty beers at the Snake & Shield. The prices? High, of course, but about what you pay at other pro sporting events.
A bigger issue: Unlike other sports, soccer has no timeouts and few breaks in play. Fans stay put to watch. The result: At halftime, 15,000 people get up to buy food or use the bathroom. And the lines at concession stands back up, blocking the concourse.
Union officials said they considered setting up switchback rope lanes, but found it would increase people's wait to be served. The team hopes a new program called Mangia, which lets fans use cell phones to have food delivered to their seats, will ease the halftime crowds.
Season-ticket holder Nathan Marinoff travels from Jersey City to see games, which proves "you can take the boy out of Philadelphia, but you can't make him root for the Red Bulls."
He thinks that the new stadium is fabulous. And that some team policies need revision.
He likens halftime crowds to "a mosh pit," and worries that medical workers won't get through in emergencies. On some of the hottest days of the summer, he noted, Union workers stopped fans from bringing in water - which sells for $4 a bottle in the stadium. Several people were felled by the heat.
Union officials note that the stadium has 14 water fountains, and say that on steamy days the team gives away water and ice.
"I think it's a terrific stadium," said Roger Allaway of Abington, author of several books on the history of soccer. "If I had to pick out one unfavorable thing, it would be the four-letter-word chants."
Contact staff writer Jeff Gammage at 215-854-2415 or firstname.lastname@example.org.