Moving Right Along on the Inclusions Table...

Martin Duerst duerst at it.aoyama.ac.jp
Mon Dec 25 05:56:54 CET 2006


At 01:44 06/12/25, John C Klensin wrote:

>--On Sunday, 24 December, 2006 18:40 +0900 Martin Duerst wrote:

>> I pretty much agree. But please note that the hyphen is NOT
>> a syntactic element, in any uses we are looking at.
>> It's the only non-alpha, non-digit, non-syntactic
>> character in ASCII domain names.
>
>It doesn't impact IDNs, but, when we start to look at IRIs and
>other pieces of syntax, the use of hyphen as a canonical
>separation marker in XML-based media types,

No, XML-based media types use a suffix of '+xml', not '-xml'.
See http://www.iana.org/assignments/media-types/application/.
There are quite a few other media types with hyphens in them,
but these hyphens serve mostly readability, and don't have
a syntactic function.

>language names,

Yes. But I don't expect many language tags in IDNs, especially
not composite tags. Also I don't expect too many of them in IRIs,
and if they appear, they would just be payload from an IRI
perspective. Also, the LTRU WG repeatedly has rejected to
open the repertoire of letters used in language tags to
non-ASCII letters, in my understanding for good reasons.

>other things that are expected to be parsed internally do bring
>it fairly close to being a syntactic protocol element.
>
>To the extent to which any of this discussion impacts
>stringprep, the interactions between stringprep and non-IDN
>protocols implies that we need to tread _very_ carefully.  

Being careful rarely hurts. But unless we have some more
pressing examples, I don't see too much of a need for care
for hyphens as syntactic elements.

Regards,    Martin.



#-#-#  Martin J. Du"rst, Assoc. Professor, Aoyama Gakuin University
#-#-#  http://www.sw.it.aoyama.ac.jp       mailto:duerst at it.aoyama.ac.jp     



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