NO! Plugins should NEVER CHECK WITH CASE-SENSITIVE ON NAMES! Umm, was that really confusing? Let me explain. Some plugins, unfortunately, code such that user names are case sensitive and that can bug out the server. For instance, let's take PermissionsEx. PermissionsEx checks if the names matches exactly in their data and this can cause unfortunate problems with ranks. For instance, someone does not enjoy their name being all upper-case (e.g. "ABS12") and would like to change it to all lower-cased (e.g. "abs12"). PeX sees this as a new user because .equals(user) doesn't match the upper cased name! So, the ranks are gone. And why does this matter? If the ranks are gone, then, you probably would've wasted like $6.99 donating for nothing, because everyone likes a rank and now because of some weird permission plugin name change thingy glitch, you don't have the rank anymore! So, you just essentially wasted money!! This also applies for plot plugins (I'm looking at you, PlotSquared) and sometimes even economy plugins. Please, do something! This happened to me and yeah... wasn't pleasant.