DALLAS -- Press pass? Got it. Laptop? Yep. Muscle shirts, short skirts and flip-flops? Stop right there.

For reporters covering Major League Baseball next season, beachwear and club outfits are no longer in fashion.

Baseball became the first major pro league in North America to issue dress guidelines for media members, putting them in writing this week at the winter meetings.

The no-wear list also includes visible undergarments, tank tops or anything with a team logo.

"This is not in response to any single incident," MLB spokesman Pat Courtney said Tuesday.

However, baseball was aware of the flap caused in the NFL when a Mexican TV reporter drew unwanted attention at the New York Jets' training camp in September 2010 and it formed a committee of executives and media representatives to work on guidelines.

The panel included female and Latin reporters and there was input from team trainers, who had health concerns about flip-flops in clubhouses and bare feet possibly spreading infections. Such footwear is no longer permitted.

The skimpy attire worn by some of the TV reporters covering the Marlins in Miami drew particular scrutiny.

"We just thought it was time to get a little organized, to put it in place before there was an incident," said committee member Phyllis Merhige, an MLB senior vice president.

"There's no one who expects reporters to wear a suit and tie," she said. "But with the advent of different media, there are now individuals who are not part of a bigger organization that may have a dress code."

The media should dress "in an appropriate and professional manner" with clothing proper for a "business casual work environment" when in locker rooms, dugouts, press boxes and on the field, the new MLB guidelines say.

Banned are sheer and see-through clothing, ripped jeans, one-shouldered, strapless shirts or clothing exposing bare midriffs. Also listed are "excessively short" skirts, dresses or shorts cut more than 3-4 inches above the knee.

The NFL, NBA and NHL do not have similar policies.

MLB and members of the Baseball Writers' Association of America who regularly cover the sport agree that most reporters are within the boundaries. At World Cup soccer matches, it's different -- reporters in press areas often come decked out head-to-toe in team regalia.

"Personally, I believe the baseball media in general could dress slightly more professionally," said San Francisco Chronicle writer Susan Slusser, recently elected vice president of the BBWAA and a member of the guidelines panel. "I think it's been a little too casual."

MLB said it would consider appropriate actions if the guidelines were broken.

"It can be a fine line. What one person views as appropriate may not be seen the same way by someone else," Courtney said.

At 81, former Marlins manager Jack McKeon has seen dress codes change a lot during more than a half-century in the game. Especially at warm-weather ballparks during the hottest summer months.

"I remember the old days, when even the people in Triple-A would wear a coat and tie," he said. "Now, it's casual. Less than casual, really.

"Today, it can look pretty sloppy. But that's not just baseball. It's generational."