HOUSTON -- Super Bowl merchandise is all over store shelves. A quick check can guarantee you don't pay for a fake of questionable quality.

The proof is in the sticker. Every piece of official NFL merchandise will have a holographic sticker, along with a tracking number.

"Even on the small items, it will have the logo there," said Curt Zupi, with CZ's Sports.

Zupi runs CZ's Sports and said that the customer isn't the only one who has to be careful. Zupi said, he too, has to watch out for counterfeiters. One questionable merchant argued with him that no one really owns the name Super Bowl.

"He told me his lawyers assured him they can't trademark the term 'Super Bowl.' I told him they have trademarked the term 'Super Bowl,'" Zupi said.

But it's not just a sticker, a logo or a name that separates the genuine from the bogus. It's also quality, according to officials.

Rachel San Miguel-Salts owns Imagine Productions and has the contract to manufacture all the NFL merchandise being sold by Reebok. She says absolutely every T-shirt she produces has to first be approved by the NFL, and then Reebok -- right down to the official sticker.

"They send us the film. They send us the holograms. They send us the garments," San Miguel-Salts said.

With the Super Bowl just days away, a Houston television station took their hidden cameras to downtown and spotted a couple of street vendors. One had a Super Bowl T-shirt he said was legitimate, but it did not have the official sticker.

"Well there was one on here," the unidentified vendor said. "I bet it got flapped off."

Another vendor also said her merchandise was legitimate, but she was being harassed by the bigger retailers.

"They're telling everybody in there I didn't buy it from the NFL," she said. "Why should they care if I'm just trying to make a little?"

Super Bowl officials warn consumers to buy NFL merchandise from an established, reputable dealer. They said most of the counterfeit merchandise comes from fly-by-night operations that suddenly pop up wherever the crowds are and disappear just as quickly.