Re: Case-sensitive status

Hi Murray!

you wrote:

> I'm aware that Scott has started the work of putting together a push to
> move SPF from an Experimental to Standards Track document within the
> IETF.  I'll be helping out where I can.

Definitely a worthwhile effort!  I've seen your recent thread on 
[email protected].

> One change I'd like to suggest has to do with the SPF results strings. 
> RFC4408 presents these status strings in a specific case.  RFC5451
> presents them in all-lowercase.  Neither one explicitly says anything
> about whether or not consumers of the results need to test them in a
> case-sensitive manner, although in a roundabout way they're
> case-insensitive because ABNF (RFC5234) says so when case-sensitivity
> isn't expressly stated.
>
> Would it break any known implementations to change them to
> all-lowercase in the new RFC, just to be consistent with other things?

I read RFC 4234 (the predecessor revision of RFC 5234) before I went and 
wrote the Mail::SPF Perl module under the assumption that the result 
codes would be interpreted case-*in*sensitively exactly because RFC 4234, 
section 2.3, "Terminal Values", said they would.  Of course Mail::SPF is 
not a *consumer* of SPF result codes, but only a producer (of Received- 
SPF headers).

The most significant consumer of SPF result codes I can think of probably 
is SpamAssassin.  There are certainly others.

From my experience I strongly doubt any significant software packages 
consuming SPF result codes do so in a case-sensitive manner, but of 
course that's only a gut feeling.

-Julian