The Unicode Consortium recommends that the tables in StringPrep be updated to encompass Unicode 3.2, which was released in March.
As a part of this release, there was one change (in addition to new characters) in case folding. The situation regarding the dotted/dotless I in the case foldings has been cleaned up by providing several options, one of which (full case folding without option T) preserves canonical equivalence (although not normalization forms -- text still needs to be normalized after case folding). http://www.unicode.org/Public/3.2-Update/CaseFolding-3.2.0.txt Mark __________ http://www.macchiato.com "Eppur si muove" ----- Original Message ----- From: "Dan Oscarsson" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Monday, May 06, 2002 01:57 Subject: Re: [idn] 1st stringprep issue: not answered and ignored > > The point that Soobok Lee shows is a very serious matter. > The requirement on the ACE form of IDNA is that the same > name must always result in the same ACE!!!! > > If doing casefolding/mapping followed by NFKC results in a > different code point sequence than doing NFC, casefolding/mapping and > NFKC again, we will get DNS lookup failures due to names do not > match. While hopefully most data entered into stringprep will > be NFC, some will not. > > If the above is true, stringprep/nameprep must be changed so that > the preparation steps for strings are: > > 1) See to that input strings is NFC. > > 2) all the steps in stringprep. > > > Dan > > -- > Below i Soobok Lee's text: > >UTC casefolding (UAX21) is made for char-by-char casefolding, not for > >combining sequences, but stringprep blindly applies UAX21 into them. > >That is not the problem of UAX21, rather of the stringprep. > > > >NFCing before casefolding solves this problem, but this suggestion > >was also ignored or not discussed in depth. > > > >Without any modificationa to UAX21 and NFKC and NFC, we could cure > >this <I><dot above> stringprep errors, simply by adding NFC in > >step zero in stringprep. > >
