I just noticed this while playing SGDKTetris (I've dubbed it that now). It may be in other games, but I preface it with this note because I modified the Controls window a bit, so it's not the normal one, and I can't look at the code because I'm currently not at my computer.
When editing the controls while playing, If an input is the left arrow, it's labeled "LeftArrow". Similarily, down arrow is "DownArrow". But up is just "Up" and right is just "Right". I don't know if these labels come directly from a compiled library (in DirectX?) so it's unchangeable or something else, but I thought I'd point it out, because it seems like a silly little blunder that would annoy somebody who's OCD (

hint, hint)