Re: Re: Case-sensitive status

On Thursday, August 11, 2011 09:36:45 PM Frank Ellermann wrote:
> Murray S. Kucherawy wrote:
> > in a roundabout way they’re case-insensitive because ABNF (RFC5234) says
> > so when case-sensitivity isn’t expressly stated.
> 
> I use your mail as found in the list archive to test that I can in
> fact send mail
> to the list, threading will likely fail.  Yes, ABNF is case-insensitive
> unless folks go to the trouble and specify cases-sensitive strings in hex.
> notation.
> 
> > Would it break any known implementations to change them to all-lowercase
> > in the new RFC, just to be consistent with other things?
> 
> It can't, because ABNF is case-insensitive ;-)  There should be test
> cases in the
> test suite covering this point, in other words, it's mostly a question
> of what is
> better readable in 4408bis.  In the prose I'd prefer the mixed case
> "as is", but
> wouldn't waste time with arguing if you think that this is confusing.
> In the ABNF
> I don't care, lower case instead of camel case is fine.
> 
> That part of the ABNF apparently only affects the Received-SPF header
> field.  Is
> there any chance to get rid of this in 4408bis, e.g., with a pointer
> to RFC 4408,
> plus some "please use RFC 5451" blurb?  Any "erratum" for Received-SPF
> should be listed, I vaguely recall that this is the case, but this could
> be buried in some "things you really do not more need to care about"
> appendix.

I wrote a reply to this once already, but my phone appears to have eaten it.

My intent is to mark Received-SPF deprecated in 4408bis and SHOULD 
authentication-results to give implementors a clear signal what they should be 
doing.  Removal is inconsistent with the backwards compatibility goal for the 
effort.  In general deprecated for one update cycle before removal is a good 
practice and I think we should follow it.

In IETF terms it would be odd to argue for removal of a widely deployed 
feature, AIUI.

Scott K