Dunno if this is known, but if you try to use a disabled fairy-type move, the game gives you several text-boxes worth of glitched gibberish text instead of the move name. Doesn't break anything, and the game doesn't even give you an error over it - it continued as normal as though the move just had a REALLY long name.
Just in case it's important, I guess? Definitely scared me for a hot second. I hadn't saved in a bit.
Cloner of items, bricker of games
The OG pokegod