> Should internals be documented?

Yes, if only for the benefit of internals hackers.  (This is not to say
that I think such documentation belongs in the man pages.)

> Just think how much easier porting would be today if no one had ever
> documented _doprnt().  :)

Perhaps not that much.  I've never seen docs on _cnt and _file and
similar "traditional" stdio internals, yet programs insist on turning
up that (ab)use them.  Personally, I think it might be better if a FILE
were a completely opaque type to user-land, that is, if <stdio.h>
didn't declare the structure contents at all.  (I don't _think_ there's
any documented, supported interface that requires user-land to allocate
one statically, or otherwise know anything at all about its contents.)

					der Mouse

			    mouse@collatz.mcrcim.mcgill.edu