Re: Matching and comparison

["Martin J. Duerst" <duerst@w3.org>]

At 21:07 00/01/19 -0800, Paul Hoffman / IMC wrote:
> At 12:19 PM 1/20/00 +0900, Martin J. Duerst wrote:
> >         Filename        : draft-skwan-utf8-dns-00.txt
> 
> Yes, there is an -02 version that is still active.

Great, thanks!

> It blithely ignores any problems it creates, such as destroying Internet 
> mail and any program that uses URLs...

I don't want to start any mail discussions, but would just like to
point out that it looks like it's right on track with other things
that have been going on around URIs. For details, please see
http://www.w3.org/International/O-URL-and-ident.html.



> >  And would it really make sense?
> 
> Yes. Unless we can definitively specify the transformation (probably during 
> normalization) for how to do case-insensitivity, we need to allow 
> case-sensitivity. Further, the lack of case sensitivity is a historical 
> aberration based on the fact that some input devices couldn't do lower-case 
> ASCII. We don't need to carry that forward (although we can certainly chose 
> to).
> 
> We're trying to open up the DNS to more people. For some of them, it is 
> insulting to require a particular case that does not match their naming 
> conventions.

That may indeed be a problem.

> Unless we can show a need for case-insensitivity *in the 
> internationalized characters*, we shouldn't force it.

The largest need, already discussed, is clearly that a lot of people
don't want to have to register ibm/ibM/iBm/iBM/Ibm/IbM/IBm/IBM to
make sure nobody else registers. And three-letter companies still
have an easy job.


> >Assume I have mycompany.com, which is case-folded, i.e. Mycompany.COM
> >gets me to the same place,, and now I create Du"rst.mycompany.com,
> >and suddenly Du"rst.Mycompany.COM isn't found anymore?
> 
> Wrong question: mycompany.com isn't internationalized. The question should 
> by "Does it make sense to have D$B—S(Jst.com be different than d$B—S(Jst.com?" I 
> believe it does if it doesn't affect the case-insensitivity of any 
> non-internationalized names.

Telling people that in an URI, domain names are case-insensitive,
but file names are/may be case-sensitive is already hard. Telling
them that a name is case-insensitive it if is ASCII only, and case-
sensitive otherwise would be a really hard job.


> Again, I believe this is a protocol issue, not a requirements issue. I 
> don't see the need for a requirement about casing, other than a requirement 
> that however the protocol deals with casing, it cannot break the rule for 
> case-insensitivity in current names.

I think we can postpone the casing issue if we agree that there
are no requirements in that area, i.e. if we think that we
can live with any solution (case-folding or not). But that's
not what you are saying, and that's not what I'm saying,
so I suggest that we put the points we came up with
(would like to be able to have the names in the appropriate
casing, would prefer not to have a strange break between
names containing only ASCII and others, would like to avoid
exponentially growing registrations to cover equivalents).


Regards,   Martin.


#-#-#  Martin J. Du"rst, World Wide Web Consortium
#-#-#  mailto:duerst@w3.org   http://www.w3.org