<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Mark,<div><br></div><div>I tried converting uppercased unicode into punycode and got only lowercased results.</div><div><br></div><div>maybe I used a bad implementation of punycode?</div><div><br></div><div>v</div><div><br><div><div>On Aug 30, 2009, at 8:13 PM, Mark Davis ⌛ wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Yes, the best way to think of Punycode is as a reversible encoding of <i>any</i> Unicode string, where the encoding only uses bytes that correspond to certain ASCII characters. Any case mapping, case or character restrictions, or prefixing (xn--) is external to Punycode proper.<br> <br>Here are some examples.<br><br>//Text => [Punycode] => Text<br><br>öbb => [bb-eka] => öbb<br> ÖBB => [BB-nha ]=> ÖBB<br>I♥NY => [INY-zx5a] => I♥NY<br><br clear="all">Mark<br> <br><br><div class="gmail_quote">2009/8/30 James Mitchell <span dir="ltr"><<a href="mailto:james.mitchell@ausregistry.com.au">james.mitchell@ausregistry.com.au</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Punycode encode copies all ASCII characters verbatim; all U-labels containing at least one ASCII letter character will exhibit this behaviour.<br> <br> Example, xn--bucher-kva decodes to bücher whereas XN--BUCHER-KVA decodes to BüCHER.<br> <font color="#888888"><br> James<br> </font><div><div></div><div class="h5"><br> > -----Original Message-----<br> > From: <a href="mailto:idna-update-bounces@alvestrand.no">idna-update-bounces@alvestrand.no</a> [mailto:<a href="mailto:idna-update-">idna-update-</a><br> > <a href="mailto:bounces@alvestrand.no">bounces@alvestrand.no</a>] On Behalf Of Vint Cerf<br> > Sent: Monday, 31 August 2009 6:28 AM<br> > To: Patrik Fältström<br> > Cc: Wil Tan; Andrew Sullivan; <a href="mailto:idna-update@alvestrand.no">idna-update@alvestrand.no</a>; John C Klensin<br> > Subject: Re: Comments on draft-ietf-idnabis-defs-10<br> ><br> > you should not be able to reproduce this if I have understood the<br> > encoding/decoding algorithm. I thought it treated upper and lower case<br> > ascii as equal value for purposes of encoding and decoding. this was<br> > to allow upper/lower case ascii to be case insensitive in the<br> > punycoding algorithm, I believe.<br> ><br> > v<br> ><br> > On Aug 30, 2009, at 3:54 PM, Patrik Fältström wrote:<br> ><br> > > On 30 aug 2009, at 20.22, Wil Tan wrote:<br> > ><br> > >> However, if certain characters in an A-label have<br> > >> been uppercased, the Punycode decoding algorithm (due to its mixed-<br> > >> case<br> > >> annotation feature) may produce invalid U-label because the ASCII<br> > >> characters<br> > >> will be in capital letter form.<br> > ><br> > > Can you give examples of when this happens? I can not see this<br> > > result in the punycode algorithm. I also just did some tests with<br> > > mixed ascii, latin and chinese characters, and can not reproduce.<br> > ><br> > > Patrik<br> > ><br> > > _______________________________________________<br> > > Idna-update mailing list<br> > > <a href="mailto:Idna-update@alvestrand.no">Idna-update@alvestrand.no</a><br> > > <a href="http://www.alvestrand.no/mailman/listinfo/idna-update" target="_blank">http://www.alvestrand.no/mailman/listinfo/idna-update</a><br> ><br> > _______________________________________________<br> > Idna-update mailing list<br> > <a href="mailto:Idna-update@alvestrand.no">Idna-update@alvestrand.no</a><br> > <a href="http://www.alvestrand.no/mailman/listinfo/idna-update" target="_blank">http://www.alvestrand.no/mailman/listinfo/idna-update</a><br> _______________________________________________<br> Idna-update mailing list<br> <a href="mailto:Idna-update@alvestrand.no">Idna-update@alvestrand.no</a><br> <a href="http://www.alvestrand.no/mailman/listinfo/idna-update" target="_blank">http://www.alvestrand.no/mailman/listinfo/idna-update</a><br> </div></div></blockquote></div><br></blockquote></div><br></div></body></html>