The National Football League has shut down sales of two locally produced T-shirts -- a "Yes We Did" shirt featuring the Lombardi Trophy and a black-and-gold "Six Burgh" T-shirt -- in the aftermath of the Steelers Super Bowl win Sunday.

The NFL sent Dan Rugh, owner of CommonWealth Press on the South Side and the Web site where the shirts were sold, a cease-and-desist order Wednesday stating use of the Lombardi Trophy design violates an NFL registered trademark and copyrighted design.

"We have also learned that your company is producing and offering for sale SIX BURGH shirts using the colors of the Pittsburgh Steelers Club," the NFL's letter stated. "These elements, particularly in combination, clearly misappropriate the goodwill enjoyed by the Pittsburgh Steelers Club, which now has won six NFL Championships."

The NFL objects to the use of the team colors or any other indication or likeness of the Pittsburgh Steelers, including the designation Sixburgh, "as that's likely to confuse consumers who might mistakenly believe that the shirts were authorized by the Steelers or the NFL," NFL spokesman Dan Masonson said.

"I didn't feel as if I was infringing on anything and as a designer, I have the utmost respect for branding, identity, etc.," Mr. Rugh said yesterday. "The very second I was informed there was an issue, I stopped."

He is no longer selling any football- or Steelers-related items in his store or on his Web site. T-shirts that were already mailed can't be recalled, but additional shirts won't be produced or sold. The NFL also has demanded a full accounting of the shirts sold.

"Normally, where there's a cease-and-desist letter, there's an established trademark right, either through common law or through a U.S. trademark registration," said Kirk Houser, vice chairman of Eckert, Seamans, Cherin & Mellott's intellectual property department. "You can register things like bottle shapes and certainly the shape of the trophy could be registered."

In an interesting twist, the NFL could receive a cease-and-desist order of its own. The NFL Shop at www.nflshop.com has been selling "Six-Burgh" T-shirts.

SmartArt, LLC of Queenstown, Md., applied for the trademark to the term "SixBurgh" on Jan. 14 for T-shirts, sweatshirts, caps and jackets and the company didn't license the term's use to the NFL. SmartArt has been marketing SIXBURGH T-shirts featuring James Harrison's signature.

"We've done well with it," said Fred Fillah, SmartArt's marketing director. "I did a lot of research on 'SixBurgh.' Prior to us trademarking it, there wasn't anything. I couldn't find it anywhere. I did due diligence. You've got to respect other people's rights and what's considered fair."

Mr. Fillah said his attorney will be investigating whether the NFL has violated his trademark.

"To the extent the term SixBurgh is being used in a context that refers to the Pittsburgh Steelers, only the team or its authorized representative, in this case NFL Properties, may use it," the NFL spokesman, Mr. Masonson said.

Although the NFL didn't cite the Coach Mike Tomlin "Yes We Can" and "Yes We Did" T-shirts in its cease-and-desist letter, Mr. Rugh removed those shirts from his Web site, too.

And perhaps with good reason.

Lawyers for The Associated Press and Los Angeles street artist Shepard Fairey are in discussions about compensation and credit from Mr. Fairey for his use of a copyrighted photo of Barack Obama to create a poster. The image has been used on hundreds of thousands of buttons and posters.

Mr. Fairey's attorney, Anthony Falzone, thinks his client is on solid legal ground.

"We believe fair use protects Shepard's right to do what he did here," Mr. Falzone, executive director of the Fair Use Project at Stanford University, told the Associated Press.

Under fair use, there can be exceptions to copyright law depending on how much of an image is used, what the new work is used for and how the original is affected by the new work, the AP reported.

Despite the trademark issues, which Mr. Rugh hopes he's cleared up to the NFL's satisfaction, he says nothing can diminish or tarnish the Steelers victory he witnessed Sunday with friends and family. It was best football game he has ever seen.

"We were going nuts the whole game. It was an emotional rollercoaster. My 1-year-old daughter, Amelia, was running around in circles screaming 'TOUCHDOWN' with her little arms in the air," he said. "It was so awesome. I will remember it forever."