Re: [idn] case folding

[Leslie Daigle <leslie@thinkingcat.com>]

Let me run out in front of the firing line and make a couple of
observations:

"Brian W. Spolarich" wrote:
> Is it possible to come up with a case-folding implementation
> that is going to satisfy the behavioural expectations of the large
> majority of the users?  I am mostly ignorant of these issues as they apply
> to the the vast majority of languages, but given the issues that have been
> raised here, I have to wonder if this is practically achievable.

I strongly agree that predicting behaviour/expectations is a lousy
way to build a protocol.

However, if we say that there is no case folding/canonicalization
(except perhaps for US-ASCII, for backwards compatibility), then

	LeChatÉmerveillant.com  and
	lechatémerveillant.com

are distinct, registrable strings.

Which should I pick to register, in order to offer my customers
the least astonishment?

And we know that ICANN gets involved when my competitor registers
the alternate form.

The point is, if we don't define (i.e., point to) the appropriate
rules for determining equivalence of character strings (NOT semantics),
then it will get sorted out in courts of law -- probably differently
in different jurisdictions.  And I don't think that serves the
PLA.

I think there are 2 separate issues here:

	. rules for determining equivalence (aka partitions) 
	  so that once one string gets registered in a TLD, the
	  other strings in the same partition are "off-limits"
	  
	. rules for determining equivalence on the fly

They are both addressed by "canonicalization", if there is a single
set of acceptable rules (and people keep pointing to the UNICODE
consortium for such), although the arguments I've seen to date
suggest that these are difficult to update/apply on the fly -- which
is why I separate out the issue of handling this stuff 'on the wire'.

Leslie.	

-- 

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"My body obeys Aristotelian laws of physics."
   -- ThinkingCat

Leslie Daigle
leslie@thinkingcat.com
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