Editor’s Note: St. Tammany Bureau Chief Sara Pagones is a member of Perseus.

Half of Slidell’s Carnival krewes received letters from the city last week outlining rules the city says they broke in 2015 and serving notice that they are on probation for the 2016 parade season — a move that came as a surprise to the parading organizations.

City officials declined to say how many organizations were involved or to provide details about their individual infractions. City Administrator Tim Mathison told krewe officials assembled in the City Council chamber Thursday that he had decided it was better not to air everyone’s dirty laundry.

City Attorney Bryan Haggerty said that while the letters are public record, the city does not have to provide them while the possibility of adjudication remains.

But officials with four of the eight krewes that paraded in 2015 — Claude, Dionysus, Perseus and the Slidell Women’s Civic Club — confirmed that they have been put on probation.

Selene, Titans and the city’s two walking parades, Mona Lisa & MoonPie and Krewe de Paws of Olde Towne, were not put on probation, representatives said. However, Selene officials said they had been informed their 2015 parade started eight minutes late.

Krewes on probation could lose their right to parade in 2017 if they commit further violations next year.

The city’s action came two days after the Slidell City Council took action to increase the number of parades in the city from eight to nine. That change was made to accommodate a new group, the Krewe of Poseidon, a coed krewe formed in January that has 348 members.

Poseidon will hold its inaugural parade Jan. 10, following the Krewe of Claude, which is traditionally the first parade of the season in Slidell.

Historically, Slidell has taken a somewhat laissez-faire approach to the parades that roll along its streets. But in 2013, the City Council adopted a 35-page ordinance that codified fees for parades and established a host of rules. Among other things, the ordinance requires each parade to have at least 10 floats with a minimum of six riders on each side.

The ordinance has been in effect for two parade seasons, but this is the first time the city has put krewes on probation, a signal that Slidell officials intend to closely enforce the new rules.

The infractions were noted in post-parade reports prepared by the Slidell Police Department.

The Krewe of Claude was put on probation for having too few floats. The Slidell Women’s Civic Club was called on the carpet for moving too slowly and having large gaps between units, as was the Krewe of Perseus.

Perseus and Dionysus also were cited for inappropriate music, and Perseus’ marshal was ejected from the parade for refusing to cooperate with police requests to speed up.

Krewe representatives seemed caught off guard by the city’s action.

Andy Frisard, captain of the all-male Dionysus, told Mathison that an email informing groups about Thursday’s meeting said failing to attend could jeopardize the privilege of parading. That wording, he said, established an unfriendly tone.

Perseus was cited for inappropriate dancing as well as music — both offenses attributed to a dance group, Extreme Voltage, that marched in the parade and apparently played recorded music that included an expletive. Although police said the group’s disc jockey stopped the song when there were complaints, the violation was still noted.

Allen Little, captain of Perseus, said the krewe informs all groups in its lineup of the city’s rules in writing. The offending group won’t be allowed to return in 2016, he said. But he fretted about the possibility that another marching group could do something else wrong next year — something impossible to predict.

Haggerty said krewes can appeal any action taken by the city. Evidence like the letter Perseus sent to marching groups and the decision to kick out a group for breaking the rules would be taken into consideration, he said.

Groups also seemed concerned about how to ensure that they move fast enough to satisfy the city. They peppered Police Chief Randy Smith with questions about who is ultimately responsible for getting the parades to roll efficiently.

Mary Clement, of the Slidell Women’s Civic Club, said after the meeting that krewes can’t really control how rapidly they move through town.

Haggerty tried to portray the enforcement action in a more positive light, pointing out that the organizations had been consulted during the years it took to draft the ordinance.

The krewes benefit from the rules because they keep the quality of Slidell’s parades high, Haggerty said. If parades are allowed to roll with too few floats or riders, spectators will spread the word that “Slidell parades stink,” he said. “You all work too hard and spend too much of your discretionary money for that to happen,’’ he added.

But he wasn’t the only one who made an economic appeal.

Krewe officials insisted that they help pump up the city coffers, and not only during parade season. Little said he spent $3,000 locally over the past two months.

Frisard asked Mathison if the city would consider halving the parade fees, which are $4,000 for a night parade, $2,000 for a day parade and $500 for a marching parade.

Mathison said the economic impact of parades is difficult to quantify but noted that the city’s costs haven’t decreased. He asked Frisard what his rationale was in seeking a 50 percent reduction.

“Because we thought it was too aggressive to ask for zero,’’ he replied.

Follow Sara Pagones on Twitter, @spagonesadvocat.