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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Due to the changes in contextual/bidi validation, Windows’ client APIs dropped the additional context/bidi checks with IDNA2008 to forward-proof ourselves against
other contextual/bidi rule changes. As our APIs are intended for client side use, we expect that labels invalid by the rules would fail to be registered, so we’re depending on the existence of a DNS record to confirm whether that’s valid or not. (Eg: we’re
depending on the registrars to do the contextual/bidi validation when registering domains).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">There are, of course, cons to that approach. And it seems like we’d still pass James’ test of whether we’re IDNA2008 or IDNA2003 (because we did test this
previously).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">And, just to be clear, our APIs are currently IDNA2008 plus UTS46 (compatibility) minus contextual/bidi validation (and have been for a while and are unlikely
to change in the foreseeable future).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">-Shawn<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> idna-update-bounces@alvestrand.no [mailto:idna-update-bounces@alvestrand.no]
<b>On Behalf Of </b>James Mitchell<br>
<b>Sent:</b> Thursday, January 16, 2014 2.58 PM<br>
<b>To:</b> Mark Davis </span><span style="font-size:11.0pt;font-family:"Segoe UI Symbol","sans-serif"">☕</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">; Anne van Kesteren<br>
<b>Cc:</b> Gervase Markham; yaojk; Paul Hoffman; PUBLIC-IRI@W3.ORG; uri@w3.org; John C Klensin; IDNA update work; www-tag.w3.org<br>
<b>Subject:</b> Re: Standardizing on IDNA 2003 in the URL Standard<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">The BIDI rule changed in IDNA2008 to allow trailing digits in RTL labels – I use this for determining whether an implementation is based on IDNA2003 or IDNA2008
(+ UTS 46 or another set of mappings).<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">Regards,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">James Mitchell<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">ARI Registry Services<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">From:
</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">Mark Davis
</span><span style="font-size:11.0pt;font-family:"Segoe UI Symbol","sans-serif";color:black">☕</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black"> <<a href="mailto:mark@macchiato.com">mark@macchiato.com</a>><br>
<b>Date: </b>Friday, 17 January 2014 12:24 am<br>
<b>To: </b>Anne van Kesteren <<a href="mailto:annevk@annevk.nl">annevk@annevk.nl</a>><br>
<b>Cc: </b>Gervase Markham <<a href="mailto:gerv@mozilla.org">gerv@mozilla.org</a>>, yaojk <<a href="mailto:yaojk@cnnic.cn">yaojk@cnnic.cn</a>>, Paul Hoffman <<a href="mailto:paul.hoffman@vpnc.org">paul.hoffman@vpnc.org</a>>, "<a href="mailto:PUBLIC-IRI@W3.ORG">PUBLIC-IRI@W3.ORG</a>"
<<a href="mailto:public-iri@w3.org">public-iri@w3.org</a>>, "<a href="mailto:uri@w3.org">uri@w3.org</a>" <<a href="mailto:uri@w3.org">uri@w3.org</a>>, John C Klensin <<a href="mailto:klensin@jck.com">klensin@jck.com</a>>, IDNA update work <<a href="mailto:idna-update@alvestrand.no">idna-update@alvestrand.no</a>>,
"www-tag.w3.org" <<a href="mailto:www-tag@w3.org">www-tag@w3.org</a>><br>
<b>Subject: </b>Re: Standardizing on IDNA 2003 in the URL Standard<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">> </span><span style="font-size:8.5pt;font-family:"Garamond","serif";color:black">The point is that in practice, it [IDNA2003] isn't fixed to Unicode 3.2.</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">It is not unlikely that an implementation that you think is following IDNA2003 (with a non-standard, larger repertoire) is actually following UTS 46.</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">If you were reverse-engineering to find out which standard an implementation was following, you'd need to query certain characters to see if they were supported,
and how. UTS 46 also allows two 'modes', for transitional and not, that you'd have to test. There is a table in <a href="http://unicode.org/reports/tr46/#Table_IDNA_Comparisons">http://unicode.org/reports/tr46/#Table_IDNA_Comparisons</a> that illustrates this.
(You'd have to look at the data tables to get a full listing.) And, of course, it is clearly possible for an implementation to be non-conformant to all of the standards we are talking about (IDNA2003, UTS 46, and IDNA2008).</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">As previously noted, however, casing differences and the 4 deviation characters take some careful checking, since there is a difference between what the implementation
accepts and what goes out 'over the wire'. And the implementation may also not be using the latest version of Unicode, which would make a difference for UTS 46 and IDNA2008.</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">BTW, there's an online demo of Unicode properties that can be used to see differences. The categories are slightly different than what is shown in the above chart,
but you can get a sense for the differences:</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black"><a href="http://unicode.org/cldr/utility/list-unicodeset.jsp?a=\p%7bany%7d&abb=on&g=idna2003+uts46+idna2008">http://unicode.org/cldr/utility/list-unicodeset.jsp?a=\p{any}&abb=on&g=idna2003+uts46+idna2008</a></span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">One way to look at UTS 46 is as a migration layer to support client implementations during the transition of registries from IDNA2003 to IDNA2008, plus a mapping
layer that can be used with straight IDNA2008.</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">> </span><span style="font-size:8.5pt;font-family:"Garamond","serif";color:black">I think I did mention earlier on UTS46 might be okay, depending on the</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:8.5pt;font-family:"Garamond","serif";color:black">details. I am hoping to hear from Mark on the matter.</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">
<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black"></span><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">I'm not sure what specific</span><span style="font-size:10.5pt;color:black"></span><span style="font-size:10.5pt;font-family:"Garamond","serif";color:black">
questions you have about UTS 46. Can you reiterate them?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black"><a href="https://google.com/+MarkDavis" target="_blank">Mark</a><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><i><span style="font-size:10.5pt;color:black">— Il meglio è l’inimico del bene —</span></i><span style="font-size:10.5pt;color:black"><o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">On Thu, Jan 16, 2014 at 12:48 PM, Anne van Kesteren <<a href="mailto:annevk@annevk.nl" target="_blank">annevk@annevk.nl</a>> wrote:<o:p></o:p></span></p>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in">
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">On Thu, Jan 16, 2014 at 11:36 AM, Gervase Markham <<a href="mailto:gerv@mozilla.org">gerv@mozilla.org</a>> wrote:<br>
> On 16/01/14 11:17, Anne van Kesteren wrote:<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">>> It's not worse if it's fully backwards compatible and mostly<br>
>> interoperable across all major clients. At that point the standard is<br>
>> just wrong.<br>
><br>
> And having a standard fixed to Unicode 3.2 is not also "just wrong"?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">The point is that in practice, it isn't fixed to Unicode 3.2. I have<br>
yet to encounter an IDNA2003 implementation that does that. It turns<br>
out the setup we have in practice is a compatible evolution.<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><br>
<br>
> And I refer you to my comments above. Problems like lowercasing (for<br>
> better or worse) are punted by IDNA2008 and are labelled as an<br>
> application-level problem. In practice, what everyone should do for best<br>
> interoperability is implement the same application-level mappings, and<br>
> implement ones which are as compatible as possible with IDNA2003.<br>
> Hence.... UTS46.<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black">I think I did mention earlier on UTS46 might be okay, depending on the<br>
details. I am hoping to hear from Mark on the matter.<br>
</span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#888888"><br>
<br>
<span class="hoenzb">--</span><br>
<span class="hoenzb"><a href="http://annevankesteren.nl/" target="_blank">http://annevankesteren.nl/</a></span></span><span style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:black"><o:p></o:p></span></p>
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