Hires: A function in SRB2 that causes sprites to shrink down to half their size. It's usually used for characters (If the spriter is too lazy to manually scale down his sprites. Which, if you're like me, is a major pain in the ass) but can technically be applied to any thing (That's any thing, not anything) in SRB2.
It's known to cause all sorts of visual oddities, including allignment errors (In OpenGL mode) screwing up the None color (Which I still say should be removed) deactivating whenever the player's flags are changed (Whatever the cause may be) and breaking the SRB2JTE shadows (Dunno if that's been fixed yet)