I was referring to CLSIDs in the Registry. As far as a user trying to navigate the registry is concerned, they're garbage that do nothing but conceal locations of things Microsoft doesn't want you to change. Aside from that, the "hiding" I referred to was things like the phrase "My Computer" or other things with a space or other character in them. Quite often, but not always, the Registry entries use another code character to represent the space. The weird thing is that if the phrase has multiple words, the coded space may only appear in one place, while the rest of it will have a normal space. so if you're looking for "My Saved Pictures", you may not find it, but you might find "My&Saved Pictures" or My&Saved&Pictures", or the spaces may just be removed altogether, and you have to figure out what that coded character actually is. Then all you end up finding is a CLSID which appears in 20 other places with hardly any indication which one will affect the option you want to change.
One specific thing it took me forever to locate a few weeks ago was the option that made Windows make "Copy to Audio CD" a context menu option for all MP3 files, even though Windows Media Player wasn't the handler of those files, and I'd disabled all Windows CD burning functions. It wasn't referenced in any of the MP3 related file type information, or any of the other files types that showed that option. I finally found it deep in some odd spot, named something like MakeCDCopy, but I don't think it was even that intuitive. I consider that "hiding" the option, when there's no way in the UI to change it, and no easy way to change it manually without having intimate knowledge of the layout of the registry and the way the programmers and marketers think.