Re: [idn] 1st stringprep issue: not answered and ignored

["Soobok Lee" <lsb@postel.co.kr>]

----- Original Message ----- 
From: "Paul Hoffman / IMC" <phoffman@imc.org>
To: <idn@ops.ietf.org>
Sent: Sunday, May 05, 2002 1:03 AM
Subject: Re: [idn] 1st stringprep issue: not answered and ignored


> At 12:59 PM +0900 5/4/02, Soobok Lee wrote:
> >Stringprep should have contained warnings about this or included new 
> >revised casefolding operatins/tables,
> >but it didn't .
> 
> Correct. This has been covered many times on the mailing list. You 
> want stringprep to change the tables issued by the Unicode Consortium 
> so that stringprep does not do NFKC the same way all other software 
> that does NFKC does. There is little support for that proposition in 
> the WG.

I am not against NFKC.  I am not proposing for modification to NFKC,
but to UAX21 casefoldings. I just pointed our that The UAX21 casefolding is 
wrong at the example.
Who had answered at my questions before your this article? 
How to measure the consensus? I have never seen this WG had discussed this issue in depth.

> 
> >  the authors and co-chairs have ignored this repeated warnings
> >without any responses in this list.
> 
> There is a big difference between "ignoring" and "disagreeing with". 
> We hear you asking over and over for something for which there is 
> little support. Are you saying that we should include the concerns of 
> every single person, even if the rest of the group disagrees with 
> them?
> 
> >Therefore,stringprep(NFC(x)) == stringprep(x)  is not guaranteed. 
> >This will cause unnoticeable failures.
> 
> Your equation is completely wrong. NFKC is part of stringprep.

Alas. You still don't get my point.

The NFC(x) above is , for example, from IRI preprocessing or HTML authoring,
which often require NFC normalization on their inputs. 
To rephrase the above equation,

"NFKC(UAX21_casefold(NFC(x))) ==  NFKC(UAX21_casefold(x)) is not guaranteed."

If you preprocess IDN with NFC, you will get different namepreped ACE labels
than before in the IDN samples including <I><dot-above>.

Soobok Lee

> 
> --Paul Hoffman, Director
> --Internet Mail Consortium