Of all things, fashion became a bargaining issue in the new contract between Caterpillar Inc. and the United Auto Workers.

The new agreement includes a ban on “competitor apparel.” The contract names 19 companies that workers can’t tout on shirts, buttons, stickers or signage while on the job.

On one hand, it’s understandable why a company would look down on seeing employees sporting a competitor’s name or logo at work. In St. Louis, it’s not as if Yadier Molina takes pre-game batting practice in a blue Cubs T-shirt.

On the other hand, it’s sad that a workplace is dispirited enough to prompt workers to want to wear competition gear. If you were to spot Ronald McDonald wearing one of those paper Burger King crowns on his head, you might wonder what’s going on at the Golden Arches.

So what sparked Caterpillar’s establishment of The Wardrobe Police?

In part, it involved UAW members sporting yellow-and-green John Deere T-shirts to work during the recent negotiations. The message: In some ways, Deere’s labor contract was viewed as fairer than Caterpillar’s.

But even before that, for years workers had been wearing competitor gear on the shop floor. Over time, Caterpillar got irked, especially when visitors would come by.

“We have customers and dealers coming through our factories almost every day,” says Caterpillar spokesman Jamie Fox. “We want them to see the pride and hard work our employees put into each product and not allow what they're wearing to distract from that.”

That’s why the contract negotiations — usually focused on weighty matters like compensation and job security — turned to fashion sense.

The company proposed a mandatory shop-floor uniform of Caterpillar shirts, offering to provide five short-sleeve and five long-sleeve. But the UAW didn’t like the implied limitation, says Randy Smith, president of Local 974.

“We firmly believe that would have denied us the right to wear a union shirt, which a lot of members do,” Smith says.

So, as a compromise, the UAW agreed to a new contract policy, called “Employer Commitment to Business Success.” It reads, “In order to ensure a positive impression of our business for our customers and dealers, who from time to time tour our facilities, the Union and the Company agree that employees will not wear competitor apparel and/or display other competitor stickers, buttons, signage, or similar items while on Caterpillar property.” It then lists 19 companies by name, ending with, “The Company has the right to modify this list at their discretion.”

The policy leaves some UAW members hot under the collar.

“What a load of crap,” one told me.

Another said, “I believe this is our freedom of speech being displayed.”

However, no member has been so riled with First Amendment fervor as to test the policy yet, says union president Smith. You can almost see something like this wending its way to the U.S. Supreme Court, which would have to make its first-ever ruling on a T-shirt.

Meanwhile, if it matters, I was told that Caterpillar makes parts for some of the companies on the banned list. In that way, UAW members claim, it’s not as if Caterpillar and the competitors are mortal enemies, so what’s the big deal? I asked Caterpillar about making parts for any of the companies, but spokesman Fox did not reply directly: “The list of companies reflects those companies that are our direct competitors in the marketplace.”

OK, fine. But it’s hard to see a big-wig customer striding through a Caterpillar plant with the intent of spending a massive wad on tractors and whatnot, yet calling off the deal because some guy is wearing a Deere shirt.

I guess it’s naive to wish that both sides could get along to the point that the contract doesn’t have to include guidelines on how to play nice. I’m not sure what the next step will be in The Great T-shirt Debate. But it’d be interesting later this year to see what happens if a shop worker were to wear a shirt saying, “My HQ moved to Chicago and all I got was this lousy T-shirt.”

Phil Luciano is a Peoria Journal Star columnist. He can be reached at pluciano@pjstar.com, facebook.com/philluciano and (309) 686-3155. Follow him on Twitter.com/LucianoPhil.