Re: [idn] Is space allowed in a hostname?

[John C Klensin <klensin@jck.com>]

--On Sunday, 07 July, 2002 10:11 -0700 Doug Ewell
<dewell@adelphia.net> wrote:

> Does the semantic distinction between 2 and ² really need to
> be preserved in domain names?  Suppose you have a company
> called Foo² ("foo-squared").  How much damage is caused if
> your Web site can be accessed not only through www.foo².com
> but also through www.foo2.com?

Doug, I don't know the answer to your question, but it takes us
onto a slippery slope.  If that site is accessible in either of
those ways, does the organization whose name is really "Foo2"
have any special claims?  Is it best to keep them separate so
that both have a shot at their names as they really write them?
And, if the answer is "no, they should be combined", how is that
position ultimately different from arguing that Foo and Föo are
really the same name?  Does this cause a whole new variety of
name dispute and dispute resolution problems?

> Can it really be possible that this whole NFKC issue was not
> adequately considered and we need to stop everything to
> revisit it?

Doug, this is more a response to Dan, since I think we may
agree.  But, since I think the question is too important to be
brushed off...

I think there is a case to be made that only a very small
percentage of the WG (and still less of the IETF) has actually
understood all (or most) of that decision and its consequences.
The percentage is clearly rising at this late date and I always
get concerned when the whole IETF seems to be taking the word of
a very small number of people that a decision that may have
far-reaching impact is correct.

But, is it worth revisiting the decision?   Much as I am
concerned about the potential for damage to the Internet
resulting from putting this stuff into the DNS, I haven't seen a
lot of justification for going around this particular loop
again.  I would feel more positive about doing so had matching
and mapping issues with pairs of characters not come up before,
but they have and people who didn't read themselves in have to
bear some of the blame.  

And, worse, we know enough about them to know that there aren't
any fixes: if superscript "2" and "2" match, then the people who
thinks they should be differentiated will scream that one can't
use one's proper name.  If they don't match, then people will
worry, with some justification, about consumer confusion and
similar problems.  There is really no correct choice, or,
ultimately, a non-arbitrary one, unless one concludes that _DNS_
internationalization is a bad idea and that it needs to be
accomplished elsewhere.

In that context, using NFKC has a huge advantage, which is that
all of the essentially-arbitrary decisions are made at once; the
main alternative seems to be for us to try to make our own
decisions about every pair (or small group) of characters in the
Unicode set.  And one of the few things I'm certain about in
this situation is that going down that path leads to madness.

     john