Subject: Re: I-D Action:draft-reschke-rfc2231-in-http-04.txt

From: Julian Reschke <[email-masked]>
Date: Sun, 04 Oct 2009 17:24:07 +0200

FYI

(this version clarifies that charset names and language tags are matched 
case-insensitively)

[email-masked] wrote:
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> 
> 	Title           : Application of RFC 2231 Encoding to Hypertext Transfer Protocol (HTTP) Headers
> 	Author(s)       : J. Reschke
> 	Filename        : draft-reschke-rfc2231-in-http-04.txt
> 	Pages           : 12
> 	Date            : 2009-10-04
> 
> By default, message header parameters in Hypertext Transfer Protocol
> (HTTP) messages can not carry characters outside the ISO-8859-1
> character set.  RFC 2231 defines an escaping mechanism for use in
> Multipurpose Internet Mail Extensions (MIME) headers.  This document
> specifies a profile of that encoding suitable for use in HTTP.
> 
> A URL for this Internet-Draft is:
> http://www.ietf.org/internet-drafts/draft-reschke-rfc2231-in-http-04.txt
> 
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
> 
> Below is the data which will enable a MIME compliant mail reader
> implementation to automatically retrieve the ASCII version of the
> Internet-Draft.
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> 
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---

From: Julian Reschke <[email-masked]>
Date: Mon, 05 Oct 2009 20:57:33 +0200

Hi,

I just noticed a problem in RFC 2231 that draft-reschke-rfc2231-in-http 
inherits:

    extended-initial-value := [charset] "'" [language] "'"
                              extended-other-values

Both charset and language can contain a single quote, so it's not the 
greatest choice as separator.

On the other hand, this doesn't seem to a problem in practice, so my 
plan for draft-reschke-rfc2231-in-http is to simply disallow single 
quotes inside charset and language.

Opinions?

BR, Julian

---

From: "Martin J. Dürst" <[email-masked]>
Date: Tue, 06 Oct 2009 12:04:41 +0900

As the secondary charset expert reviewer, I have never seen a charset 
with a "'" in it. There is note at 
http://www.iana.org/assignments/character-sets, and they are not allowed 
in the "more restrictive" production in Section 2.3 of RFC 2978. They 
are also not allowed in XML, which is even more restrictive. I guess 
that as a reviewer, I'd simply tell an applicant to change the name.

As the co-chair of the LTRU WG, I know quite for sure that language tags 
don't contain "'". Please check yourself at 
http://tools.ietf.org/html/rfc5646 or one of it's predecessors.

So I see absolutely no problem to tightening up the grammar.

Regards,    Martin.

-- 
#-# Martin J. Dürst, Professor, Aoyama Gakuin University
#-# http://www.sw.it.aoyama.ac.jp   mailto:[email-masked]

---

From: Julian Reschke <[email-masked]>
Date: Tue, 06 Oct 2009 10:20:34 +0200

Hi Martin,

thanks for the confirmation.

> that as a reviewer, I'd simply tell an applicant to change the name.

As a matter of fact, I'm not sure why I made it "token" in the first place.

> http://tools.ietf.org/html/rfc5646 or one of it's predecessors.

Right, and the ABNF was already referring there; so again no problem.

Checking: is there a simpler ABNF somewhere to extract "potential" 
language tags from other text content? It appears that they are 
restricted to:

   *( ALPHA / DIGIT / "-" )

right?

 > ...

Best regards, Julian