In <4297671C(_dot_)5F64(_at_)xyzzy(_dot_)claranet(_dot_)de> Frank Ellermann
<nobody(_at_)xyzzy(_dot_)claranet(_dot_)de> writes:
Julian Mehnle wrote:
"SHOULD/RECOMMENDED" != required.
You need excellent technical reasons to violate a SHOULD.
Like an old application implemented before the SHOULD.
Or a situation where it's obviously dubious, for SPF the
post-SMTP stuff is among the usual suspects. Or for the
HELO-test if you already have a good CSV result.
"I don't like it" is not good enough to violate a SHOULD,
in that case I'd recommend s/SHOULD/MAY/ as it was in the
mengwong drafts.
RFC2119 says:
3. SHOULD This word, or the adjective "RECOMMENDED", mean that there
may exist valid reasons in particular circumstances to ignore a
particular item, but the full implications must be understood and
carefully weighed before choosing a different course.
While, "I don't like it" is not good enough, I think "it is not worth
the DNS lookups" is perfectly ok, as long as people understand the
implicatiions.
Of course, in the real world, people ignoire MUST and REQUIRED all the
time, treating them as barely more than MAY.
-wayne