How MD are .hi files?

Hi, for an unregisterised ghc-6.8.2 (or newer), are the .hi files dependent (except for the 32 vs. 64 bit word size)? I had a quick look at the stuff in compiler/iface, but the only MD part I found was that 32/64 bit difference. TIA Ciao, Kili ps: if you think this sounds like a complete newbie question, you're right; I've been far too busy hacking on boring stuff like Makefiles, and didn't have time to look at the interesting code (i.e. ghc itself). My knowledge of ghc's internals is at the state of 1998, or even older, I really don't remember ;-) -- Options are good. As long as they are optional. -- Artur Grabowski