What are official terms your fandom refuses to use?

The biggest example I know is Granblue. Every guide for new players was confusing because the official name of a weapon series is called the Omega series. The fanbase calls them "Magna."

What are super attacks officially? Charge Attacks. What does the fanbase call them? Ougi. And if they want to shorten it, they say CA. So they acknowledge Charge Attack exists, but not for longform.

You still see it in Granblue Rising when people call potato man Anre "Uno."