[Simon Young]

Like, say if I renamed my personal files so that "Lord of the Rings.mov" became "Lord of the Rings"? Would it stop the files working, or would they still safely be associated with the correct app? What's the point of having the extension anyway? Windows doesn't show them by default, and it seems silly that Mac OS 9 doesn't have a way to switch them off.

[philzilla]

yes, you can. mac os doesn't rely on extensions to tell it what's going on, it uses creator/file type aliens, which live inside each file and tell your mac what to open it with.

i hate the way you can, say, rename an .exe file to .pdf in Windoze and then, lo and behold... it's an Acrobat file, complete with icon! duuuuh.

i'm led to believe OS X uses a combination of both though. hmm.