Taco Johns has agreed to drop its trademark registration of "Taco Tuesday" after Taco Bell and an NBA athlete intervened. Taco Bell petitioned to have the registration killed, arguing that it is a common phrase. The outcome of this battle is that Taco Tuesday may now be used by anyone.
https://www.jdsupra.com/legalnews/taco-tuesday-for-all-3774730/
https://www.jdsupra.com/legalnews/taco-tuesday-for-all-3774730/