RE: SHOULD vs MUST case sensitivity

"Eric Gray" <> Mon, 30 June 2008 13:51 UTC

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Subject: RE: SHOULD vs MUST case sensitivity
Date: Mon, 30 Jun 2008 08:52:09 -0500
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Thread-Topic: SHOULD vs MUST case sensitivity
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From: "Eric Gray" <>
To: "Dave Crocker" <>, "Randy Presuhn" <>
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	Let's try to close this argument in a constructive way.

	We could argue the extent to which "Best Current Practice"
RFCs actually specify anything - rather than simply encouraging
a commonly accepted practice.  Based on that argument - and lots
of usage evidence (represented - among other things - by text 
you've quoted) - RFC 2119 appear to state that the terms in 
question are often capitalized.  And that supports a further
argument that RFC 2119 is suggesting this should be the case -
given that it is a common practice.

	We could also make the semantic argument that you've made
- i.e. - that capitalization is not essential to the semantics
that RFC 2119 encourages RFC authors to use.  It is certainly 
going to be the case that some RFCs will be published with the
intent for these terms to be normative, and where not every 
instance is in ALL-CAPS - and this should not mean necessarily
that these words are not meant to be taken as normative.

	However, there is abundant evidence to support argument
that prospective RFC authors should use the ALL-CAPS version of
these words - if for no other reason than because it removes any
possibility of doubt.  The evidence to support this is based at
least partly on current usage - such as a BCP like RFC 2119 is
meant to reflect.  It is also based at least in part on the the
arguments put forward in this thread.  And finally, it is based
at least in part on the common-sense proposition that anything
that adds clarity to a specification is generally a good thing.

	Hence I believe the one thing we should take away from
this discussion is that - while use of the ALL-CAPS version of
the requriements level terminology in RFC 2119 is probably not 
technically required to indicate the intended usage - it is a 
very good idea to do this.  Further, if we assume that is the
case (and I think reasonable people will agree that it is),
then continuing the argument about the semantics in this case
is merely a distraction from useful discussion and clarity in
the work we all want to be doing.

Eric Gray
Principal Engineer

> -----Original Message-----
> From: [] On 
> Behalf Of Dave Crocker
> Sent: Sunday, June 29, 2008 10:32 PM
> To: Randy Presuhn
> Cc: IETF Discussion
> Subject: Re: SHOULD vs MUST case sensitivity
> Randy Presuhn wrote:
> >> English is not case sensitive.
> > 
> > Not so.  Case has long been used for emphasis in environments
> > lacking other typographical means, such as bolding, underlining,
> > or italicization.
> Emphasis is not semantics.
> Normative intent is semantic.
> d/
> -- 
>    Dave Crocker
>    Brandenburg InternetWorking
> _______________________________________________
> Ietf mailing list
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