[From nobody Wed Sep 16 04:53:46 2009 X-HELO: ehlo mail.nic.or.kr X-RECEIVED-IP: 202.30.50.51 Received: from 202.30.50.51(202.30.50.51) at Sat, 12 Sep 2009 05:20:00 +0900 by nida.or.kr with ESMTP CrediShield X-MAIL-FROM: idna-update-bounces@alvestrand.no Received: from nida.or.kr (mailgw.nic.or.kr [202.30.50.169]) by mail.nic.or.kr (v3smtp 8.11.6.9/8.11.0) with SMTP id n8BKJf210847 for <yjsuh@nida.or.kr>; Sat, 12 Sep 2009 05:19:41 +0900 (KST) X-HELO: ehlo eikenes.alvestrand.no X-RECEIVED-IP: 158.38.152.233 Received: from 158.38.152.233(158.38.152.233) at Sat, 12 Sep 2009 05:19:40 +0900 by nida.or.kr with ESMTP CrediShield X-MF: _EngSubj=-0.10 X-MAIL-FROM: idna-update-bounces@alvestrand.no Received: from localhost (localhost [127.0.0.1]) by eikenes.alvestrand.no (Postfix) with ESMTP id 022F639E12B; Fri, 11 Sep 2009 22:19:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at eikenes.alvestrand.no Received: from eikenes.alvestrand.no ([127.0.0.1]) by localhost (eikenes.alvestrand.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id If2l81F28+yt; Fri, 11 Sep 2009 22:19:32 +0200 (CEST) Received: from eikenes.alvestrand.no (localhost [127.0.0.1]) by eikenes.alvestrand.no (Postfix) with ESMTP id 5F35E39E1BB; Fri, 11 Sep 2009 22:19:27 +0200 (CEST) X-Original-To: idna-update@alvestrand.no Delivered-To: idna-update@alvestrand.no Received: from localhost (localhost [127.0.0.1]) by eikenes.alvestrand.no (Postfix) with ESMTP id D5BCB39E177 for <idna-update@alvestrand.no>; Fri, 11 Sep 2009 22:19:25 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at eikenes.alvestrand.no Received: from eikenes.alvestrand.no ([127.0.0.1]) by localhost (eikenes.alvestrand.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id I2t8snDcauCK for <idna-update@alvestrand.no>; Fri, 11 Sep 2009 22:19:21 +0200 (CEST) X-Greylist: delayed 00:08:17 by SQLgrey-1.6.8 Received: from QMTA10.emeryville.ca.mail.comcast.net (qmta10.emeryville.ca.mail.comcast.net [76.96.30.17]) by eikenes.alvestrand.no (Postfix) with ESMTP id F1C8639E12B for <idna-update@alvestrand.no>; Fri, 11 Sep 2009 22:19:20 +0200 (CEST) Received: from OMTA03.emeryville.ca.mail.comcast.net ([76.96.30.27]) by QMTA10.emeryville.ca.mail.comcast.net with comcast id fVMR1c0040b6N64AAYB2Xg; Fri, 11 Sep 2009 20:11:02 +0000 Received: from nicemice.net ([67.170.13.46]) by OMTA03.emeryville.ca.mail.comcast.net with comcast id fYB01c0030zd4JB8PYB1dL; Fri, 11 Sep 2009 20:11:02 +0000 Received: from amc by nicemice.net with local (Exim 4.69) (envelope-from <return.amc+0+@nicemice.net>) id 1MmCSQ-0007XZ-Vf; Fri, 11 Sep 2009 13:10:58 -0700 Date: Fri, 11 Sep 2009 20:10:58 +0000 From: "Adam M. Costello" <idna-update.amc+0+@nicemice.net.RemoveThisWord> To: Martin =?iso-8859-1?Q?J=2E_D=FCrst?= <duerst@it.aoyama.ac.jp> Subject: Re: Definitions limit on label length in UTF-8 Message-ID: <20090911194239.7az~@nicemice.net> References: <a617d24ceb7e3d66f9d6bd1ee7162e61@localhost.localdomain> <B60A675C-8A18-4F55-82BB-5DCB11236403@google.com> <4AA8D415.70207@it.aoyama.ac.jp> <20090910153142.GE53599@shinkuro.com> <B5882658E1993671ABAAAC42@PST.JCK.COM> <4AA9CFF8.8060605@it.aoyama.ac.jp> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4AA9CFF8.8060605@it.aoyama.ac.jp> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: Andrew Sullivan <ajs@shinkuro.com>, idna-update@alvestrand.no, John C Klensin <klensin@jck.com> X-BeenThere: idna-update@alvestrand.no X-Mailman-Version: 2.1.9 Precedence: list Reply-To: IDNA update work <idna-update@alvestrand.no> List-Id: IDNA update work <idna-update.alvestrand.no> List-Unsubscribe: <http://www.alvestrand.no/mailman/listinfo/idna-update>, <mailto:idna-update-request@alvestrand.no?subject=unsubscribe> List-Archive: <http://www.alvestrand.no/pipermail/idna-update> List-Post: <mailto:idna-update@alvestrand.no> List-Help: <mailto:idna-update-request@alvestrand.no?subject=help> List-Subscribe: <http://www.alvestrand.no/mailman/listinfo/idna-update>, <mailto:idna-update-request@alvestrand.no?subject=subscribe> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: idna-update-bounces@alvestrand.no Errors-To: idna-update-bounces@alvestrand.no "\"Martin J. D=FCrst\"" <duerst@it.aoyama.ac.jp> wrote: > [Short summary: It's very easy to create UTF-8 strings that are longer > than punycode, for everything except US-ASCII. Remember, punycode was > *designed* to be efficient, in particular for domain name labels.] Of the 11 languages I tried for my ACE evaluation, five were more compact in Punycode than in UTF-8 for my example sentence ("Why can't they just speak <language>?"). Arabic: Punycode: xn--egbpdaj6bu4bxfgehfvwxn UTF-8: ?????????????????????????????????? Hebrew: Punycode: xn--4dbcagdahymbxekheh6e0a7fei0b UTF-8: ???????????????????????????????????????????? Hindi (Devanagari): Punycode: xn--i1baa7eci9glrd9b2ae1bj0hfcgg6iyaf8o0a1dig0cd UTF-8: ???????????????????????????????????????????????????????????????= ??????????????????????????? Japanese (kanji and hiragana): Punycode: xn--n8jok5ay5dzabd5bym9f0cm5685rrjetr6pdxa UTF-8: ?????????????????????????????????????????????????????? Russian: Punycode: xn--b1abfaaepdrnnbgefbaDotcwatmq2g4l UTF-8: ?????????????????????????????????????????????????????????? > People not familiar with the history of the development of IDNA2003 > should be aware of the fact that a lot of energy went into the > development of compression algorithms for domain names, I can confirm that. :) > The "max 63 octets in UTF-8" provision, unless removed, negates all > this effort. Yeah, that would be a shame. Since I haven't had time to participate in IDNA2008, maybe I haven't earned the right to comment, but... A real concern back then was that IDNA would be unfair to non-ASCII scripts, because they couldn't fit nearly as much text in a domain label. Making it truly fair was never possible, but we did work very hard to find an encoding that could squeeze as much non-ASCII text as possible into a 63-byte ACE label. If a 63-byte limit on UTF-8 forms is imposed, the complexity of Punycode is largely wasted and/or misdirected; the encoding should have been designed to be just complex enough to beat UTF-8, not to be as compact as possible. Also, I agree with Martin's concern that adding a 63-byte limit on the UTF-8 form of labels would have greater cost than benefit. The cost is breaking compatibility with names that are valid in IDNA2003. AMC _______________________________________________ Idna-update mailing list Idna-update@alvestrand.no http://www.alvestrand.no/mailman/listinfo/idna-update ]