The "Boston Strong" catchphrase coined following the Boston Marathon bombings to describe the city’s resiliency is at the center of a trademark tug of war.

Two applicants filed for the mark with the U.S. Patent and Trademark Office on April 17. Kerim Senkal of Allston, Mass., filed an application to trademark messages on T-shirts and other apparel, accessories and mugs. Born Into It Inc. of Woburn, Mass., which also does business as Chowdaheadz, filed an application to use the mark on clothing and accessories.

Trademark lawyers expressed doubts about whether the phrase could be trademarked, and about its usefulness. "It’s not a real strong mark in the sense that the word ‘Boston’ is in it," said Toby Kusmer, a Boston partner at McDermott Will & Emery whose practice includes trademark law but is not involved in this matter.)

Trademark law doesn’t allow geographically descriptive marks, so any trademark wouldn’t protect anyone else’s use of a two-word phrase that starts with the word "Boston." Using it on a consumer item like a T-shirt, for example, would also require a tag that says something like "Boston Strong brand," because if the phrase is just rendered as artwork, doesn’t constitute trademark use, he said.

"Trademark law on its face it seems simple, but when you get into this stuff, there’s a lot of subtlety," Kusmer said.

Another barrier is that trademark law generally protects brands, said Rod Berman, a partner at Los Angeles-based Jeffer Mangels Butler & Mitchell. Berman also isn’t involved in the case. "It can’t be something that’s simply laudatory," Berman said.

Even if one of the parties secures limited trademark rights, the law doesn’t bar others from using the phrase in a descriptive way, he said. The First Amendment also would protect third parties using the same or a similar phrase.

Since both parties filed on the same date, who wins would probably come down to the time of filing, he added.

Senkal declined to comment. Born Into It responded to a request for comment by noting a long statement on its company blog.

The statement said the company decided to create some T-shirts "with the mission of donating a large portion of the proceeds to the fund setup by the [The One Fund Boston charitable fund for marathon victims]." Any donation would be based on total online sales, not sales of "a few select items."

"Everyone on the Chowdaheadz team has grown up in the Boston area and we very much consider ourselves and our company a part of the community," the statement continued.

The company called its filing a "defensive measure to protect not only us but others from being bullied by another party trying to use this trademark in bad faith."

Sheri Qualters is a reporter for The National Law Journal, a Legal affiliate based in New York.