You’ve probably seen #TacoTuesday all around the internet. If you haven’t seen it, chances are you’ve probably heard it in conversation or even said it yourself. It’s the perfect way to bring attention to your photos of fish tacos or show your love for the delicious dish.

But where did that phrase actually come from? And is it actually okay for us to use? The answers may surprise you.

In Texas, you might notice that the hashtag isn’t used as much as you think it would be. There is a big reason behind that, and the name Taco John’s is key. The Wyoming-based restaurant named Taco John’s actually started the hashtag, and if anyone else tries to use it, they might be sued. Since 1989, the restaurant has had ownership of the phrase and doesn’t hesitate to stop anyone who tries to use it. They actually went after an Oklahoma City grill in 2010 for trying to use the trademarked words.

When Taco John’s became using the phrase back in the 1980’s, they noticed an increase in their business and haven’t stopped using it since. The chain has sent out hundreds of cease-and-desist orders to this day trying to get other places to stop using their famous phrase.

Inspiringly enough, Taco John’s only owns the trademark in 49 states out of 50. New Jersey isn’t actually “owned” by the chains. Back in 1979, Greg Gregory trademarked the phrase for his state. Everyone there is still allowed to use it.

A big reason why those who own Taco John’s doesn’t want “Taco Tuesday” to be used is because they feel like it’s theirs and doesn’t want it to become part of the common public word usage. They want it to be theirs and only theirs. They also want to make sure that people come into their restaurant, knowing that it’s the only place where it’s okay to use the phrase. It adds novelty to the word to know that you’re eating in the place where the fun phrase originated.

Americans eat over 4 billion tacos a year, so it’s definitely a popular Mexican food. Anyone interested in hosting their own taco party can do so if they wish. They can use casual catering to provide the tacos and Mexican dishes. Aside from the casual catering and the tacos themselves, they just need to be sure not to use the phrase “Taco Tuesday” to prevent being sued.