Re: "conformance" vs. compatibility

[ari]

address@hidden said this stuff:

> After 10 years of being merely `obsolescent', head -N has finally
> been officially declared to be `obsolete'.

I have yet to see a pointer to where the historic usage has been
declared "obsolete", outside of personal declarations that it has been
"officially declared obsolete" elsewhere.  Surely, you can't mean to
imply that merely because it has been withdrawn from the posix
guidelines, it has become obsolete.  This would be a misinterpretation
of posix in general.  The authors of the posix guidelines have simply
opted to not discuss it further, just as they don't discuss 'head -c'.
That is, aside from an informational note, mentioning that they have
intentionally left the '-c' option out --- which, coincidentally,
doesn't make it obsolete, either.

If i'm mistaken, please do point me to this official declaration.  If
you have no official declaration, at least point me to an excerpt in the
posix publication stating, definitively, that when a feature is
withdrawn from posix, it becomes officially obsolete for
posix-conforming implementations.

ari