On 25/06/2013 08:38, John C Klensin wrote:
--On Monday, June 24, 2013 16:28 -0400 Alia Atlas
<akatlas(_at_)gmail(_dot_)com> wrote:
I read SHOULD and RECOMMENDED as different.
SHOULD is how a implementation ought to behave unless there
are special circumstances (deployment, additional
functionality, better idea). MUST says that there are no
circumstances special enough to change the behavior.
RECOMMENDED is closer to a Best Current Practice (BCP); so I
might write "It is RECOMMENDED that the network-converged
timer have a minimum value of 2 seconds." but in 10 years,
maybe it'll only take 2 microseconds - so that'll become a bad
recommendation!
And that, again, is close to the distinction that a reasonable
person might read into 2026. But not into 2119 which appears
(at least to me) to make them fully-substitutable alternatives.
The distinction doesn't make the comments made by Peter, Dave,
or others any less valid. If we told ourselves that readers
should (lower case) infer conformance statements from SHOULD and
applicability ones from RECOMMENDED... well, we would be pretty
delusional.
Also, issuing 2119bis with a subtle difference between the two
would create a horrible problem of interpretation for all existing
documents (including numerous documents from other SDOs) that
explicitly cite 2119. This has ramifications that make my head hurt.
Brian