Wyoming-based fast-food restaurant Taco John’s was issued a federal trademark for TACO TUESDAY back in 1989. Readers may be surprised to hear this, as the phrase sounds pretty, well, generic. Several media sources report that Taco John’s sent a cease-and-desist letter to Freedom’s Edge Brewing Co. — mere blocks from the Mexican-themed restaurant’s headquarters in Cheyenne — because Freedom’s Edge used TACO TUESDAY to advertise a taco truck that parks outside the brewery on Tuesdays.

USA Today cites a Seattle lawyer for his opinion that TACO TUESDAY is too familiar to belong to one owner and that it is an example of genericide or genericization, meaning the phenomenon of public use of a term so wide that it can no longer be owned as a brand that functions as a trademark by indicating a single source, as opposed to identifying a mere thing that may come from countless sources like “nylon,” “aspirin” or “escalator.”

Apparently, Taco John’s is fighting hard to keep Taco Tuesday in its trademark arsenal. Thrillist reports that they continue to send cease-and-desist letters to smaller restaurants, that their website talks about the trademark and that a company spokesperson said that the phrase is “part of [its] DNA … this American institution …”

The Thrillist article reproduces old ads using the phrase and explains that the its use goes back decades before Taco John’s claimed it. But the 1989 mark was granted and it will be interesting to see if Taco John’s is able to protect it from becoming too generic.

An interesting aside: Taco John’s TACO TUESDAY federal registration covers the entire U.S. except for the state of New Jersey. Both Taco John’s and a New Jersey company claim first use going back to 1979. Following a “concurrent use proceeding” before the Trademark Trial and Appeal Board, territorial rights were decided or agreed under a “coexistence agreement” to be allocated as described above.