<font size="2">I agree with Erik. The structure of the document makes it hard to disentangle the perceived problems from the proposed solutions, and many of the perceived problems don't have enough justification for how severe those problems really are. One should be able to read the document, and be able to then say: "There are 10 problems outlined in the document, and for each problem these are the proposed solutions, or a conclusion that a solution is infeasible or best handled with a different mechanism". That is difficult to do currently.
<br><br>I'd strongly recommend a more systematic structure, as something like:<br></font><ul><li><font size="2"><span style="font-weight: bold;">Background: </span>A brief overview of what IDNA is, and how it is used. No interwoven perceived problems.
<br></font></li><li><font size="2"><span style="font-weight: bold;">Problems: </span>What are the perceived problems with IDNA. No interwoven propose solutions.<br></font></li><li><font size="2"><span style="font-weight: bold;">
Solutions: </span>Possible solutions for each of the perceived problems, or conclusions that the cost/benefit analysis does not support making a change for the problem.<br></font></li><ul><li><font size="2">eg, that the perceived problem is not that serious, or that there does not seem to be a feasible solution
in IDNAbis such as in <span>"8. The Ligature and Digraph Problem"</span><br></font></li></ul></ul><font size="2"><span style="font-weight: bold;"><span style="font-weight: bold;"><span style="font-weight: bold;">
<span style="font-weight: bold;"></span><br></span>Background<br></span></span>For the background, I'd recommend the following. Much of this is already there, but spread around.<br></font><ol><li><font size="2">Quick discussion of what is permitted and what isn't, with examples
</font></li><li><font size="2">The registration scenario</font></li><li><font size="2">A usage scenario (eg typing or copying text in the address bar of a browser)
</font></li></ol><font size="2"><span style="font-weight: bold;"><span style="font-weight: bold;">P</span>erceived problems<br></span>For the perceived problems, at a top level I see at least the following, of which the first two are core issues.
<br style="font-weight: bold;"></font><ol><li><font size="2">IDNA disallows labels that some people want. Examples:<br></font></li><ol><li><font size="2">Unicode 3.2 characters: Catalan "xarel·lo", Farsi <Noon, Alef,
Meem, Heh, ZWNJ, Alef, Farsi Yeh>,..., trailing combining marks in BIDI fields.<br></font></li><li><font size="2">Unicode 4.0+ characters: words with Oriya WA or VA, Bengali KHANDA TA, Tamil SHA, Ethiopic HOA, Balinese characters (should get specific example),...
<br></font></li></ol><li><font size="2">IDNA allows labels that some people don't want. There are two main categories:<br></font></li><ol><li><font size="2">Security issues: "<a href="http://amazon.com/bogus.com">
amazon.com/bogus.com</a>", where the "/" is a fraction slash, "<a href="http://paypal.com">paypal.com</a>" with Cyrillic 'a',...</font></li><li><font size="2">Not Security issues, but "not necessary": eg
<span style="font-weight: bold;"></span><a href="http://i%e2%99%a5ny.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">I♥NY.<span id="st" name="st" class="st">museum</span></a></font></li></ol>
<li><font size="2"><span id="st" name="st" class="st">The accepted input set is much larger than the output set, and should be restricted (example: "<a href="http://fishing.com">fishing.com</a>" with an "fi" ligature).* (Needs a discussion of why this is a problem.)
<br></span></font></li><li><font size="2">The process of upgrading to new versions of Unicode is slow, thus disadvantaging minority scripts<br></font></li><li><font size="2">User's expectations are not met when an IDN that seems perfectly reasonable, like
<span style="font-weight: bold;"></span><a href="http://b%c3%a4cker.com/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">bäcker.com</a>, don't either display or work in some applications.*</font>
</li><li><font size="2">The definition of IDNA2003 as an explicit algorithm, expressed partially in prose and partially in pseudocode, rather than more traditional IETF practice where the functions are specified, rather than algorithm.*
</font></li><li><font size="2">Character conversion may cause a problem if the characters of the local character set do not map exactly and unambiguously onto Unicode characters.*</font></li><li><font size="2">Display ordering can be different than network (logical) order.*
</font></li><li><font size="2">Some sequences are considered equivalent in one language, but not in another (æ vs ae vs <span>ä</span>)*<br></font></li></ol><font size="2"><span>For user expectations, </span>we should have a table of examples for such cases, such as:
<br><br></font><table border="1" cellpadding="2" cellspacing="0"><tbody><tr><td style="font-weight: bold;"><font size="2">URL</font></td>
<td style="font-weight: bold;"><font size="2">IE 7 <br></font>
</td>
<td style="font-weight: bold;"><font size="2">Firefox 2.x<br></font>
</td>
<td style="font-weight: bold;"><font size="2">Opera 9.1 <br></font>
</td>
</tr>
<tr>
<td><font size="2"><span style="font-weight: bold;"><a href="http://www.%c3%beorn.is/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">www.þorn.is</a></span></font></td>
<td><font size="2"><a href="http://www.%c3%beorn.is/" title="'þ' is Latin. Displays fine if you have any language that uses 'ä' selected in your preferences" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
www.þorn.is</a></font></td>
<td><font size="2"><a href="http://www.%c3%beorn.is/" title="'þ' is Latin. Firefox trusts IDNs in the .is TLD" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">www.þorn.is</a></font></td>
<td><font size="2"><a href="http://www.%c3%beorn.is/" title="'þ' is Latin. Opera trusts IDNs in the .is TLD" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">www.þorn.is</a></font></td>
</tr>
<tr>
<td><font size="2"><span style="font-weight: bold;"><a href="http://b%c3%a4cker.com/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">bäcker.com</a></span></font></td>
<td><font size="2"><a title="'ä' is Latin. Displays fine if you have any language that uses 'ä' selected in your preferences" href="http://xn--bcker-gra.com/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
bäcker.com/</a></font></td>
<td><font size="2"><a title="Firefox does not trust IDNs in .com domain" href="http://xn--bcker-gra.com/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">xn--bcker-gra.com/</a></font></td>
<td><font size="2"> <a title="Opera trusts IDNs in .com domain" href="http://xn--bcker-gra.com/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">bäcker.com/</a></font></td>
</tr>
<tr>
<td><font size="2"><span style="font-weight: bold;"><a href="http://%d0%bf%d1%83%d1%82%d0%b8%d0%bd.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">путин.<span id="st" name="st" class="st">
museum</span></a></span></font></td>
<td><font size="2"><a title="Displays properly if language preferences include Russian" href="http://%d0%bf%d1%83%d1%82%d0%b8%d0%bd.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">путин.<span id="st" name="st" class="st">
museum</span></a></font></td>
<td><font size="2"><a title="Firefox trusts the .museum top level domain" href="http://%d0%bf%d1%83%d1%82%d0%b8%d0%bd.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">путин.<span id="st" name="st" class="st">
museum</span></a></font></td>
<td><font size="2"> <a title="Opera trusts the .museum top level domain" href="http://%d0%bf%d1%83%d1%82%d0%b8%d0%bd.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">путин.<span id="st" name="st" class="st">
museum</span></a></font></td>
</tr>
<tr>
<td><font size="2"><span style="font-weight: bold;"><a href="http://i%e2%99%a5ny.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">I♥NY.<span id="st" name="st" class="st">museum</span></a></span>
</font></td>
<td><font size="2"><a title="'♥' is not part of any language" href="http://i%E2%99%A5ny.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">xn--iny-zx5a.<span id="st" name="st" class="st">
museum</span>/</a></font></td>
<td><font size="2"><a title="Firefox trusts the .museum top level domain" href="http://i%e2%99%a5ny.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">i♥ny.<span id="st" name="st" class="st">
museum</span>/</a></font></td>
<td><font size="2"> <a title="Opera trusts the .museum top level domain" href="http://i%e2%99%a5ny.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">i♥ny.<span id="st" name="st" class="st">museum
</span>/</a></font></td>
</tr>
<tr>
<td><font size="2"><span style="font-weight: bold;"><a href="http://p%d0%b0ypal.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">pаypal.<span id="st" name="st" class="st">museum</span></a></span>
</font></td>
<td><font size="2"><a title="'a' is Cyrillic. Even if Russian is in language settings, it displays as punycode - anything looking like 'paypal' is blacklisted." href="http://p%D0%B0ypal.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
xn--pypal-4ve.<span id="st" name="st" class="st">museum</span>/</a></font></td>
<td><font size="2"><a title="Firefox trusts the .museum top level domain" href="http://p%d0%b0ypal.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">pаypal.<span id="st" name="st" class="st">
museum</span>/</a></font></td>
<td><font size="2"> <a title="Opera trusts the .museum top level domain" href="http://p%d0%b0ypal.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">pаypal.<span id="st" name="st" class="st">
museum</span>/</a></font></td>
</tr>
<tr>
<td><font size="2"><span style="font-weight: bold;"><a href="http://ibm.com%e2%81%84foo.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">ibm.com⁄foo.<span id="st" name="st" class="st">museum
</span></a></span></font></td>
<td><font size="2"><a title="URL uses the 'fraction-slash' - not part of any language" href="http://ibm.xn--comfoo-rq0c.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">ibm.xn--comfoo-rq0c.
<span id="st" name="st" class="st">museum</span></a></font>
</td>
<td><font size="2"><a title="'fraction-slash' character is treated suspiciously by Firefox" href="http://ibm.xn--comfoo-rq0c.museum/" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">ibm.xn--comfoo-rq0c.
<span id="st" name="st" class="st">museum</span>/
</a></font></td>
<td style="font-style: italic;"><font size="2">Illegal </font></td></tr></tbody></table><font size="2"><br></font><div><font size="2"><span class="gmail_quote">I drew the * problems from <a href="http://www.ietf.org/internet-drafts/draft-klensin-idnabis-issues-00.txt">
http://www.ietf.org/internet-drafts/draft-klensin-idnabis-issues-00.txt</a>. I may have missed some, since they are interwoven in the text.<br><br>In all cases, I think they need motivating examples. For example, for the claim that "
</span>Character conversion may cause a problem if the characters of the local
character set do not map exactly and unambiguously onto Unicode
characters." one should be able to cite at least one charset where at least one character conversion causes a problem for IDNA2003. Either that, or remove it as a problem.<br><br>Such examples are <span style="font-style: italic;">
extremely </span>helpful for having a concrete set of cases, rather than abstractions that are difficult to assess -- and more importantly, difficult to say whether a particular solution addresses the particular examples cited.
<br><br>In some cases there are already such extensive examples and discussion in issues-00. For example, the display order being different than network order, or the ligature ae issue. In other cases they are missing. I understand that you can't address everything at this point, so indicating where missing material is TBD is certainly reasonable.
<span class="gmail_quote"><br><br><span style="font-weight: bold;"><span style="font-weight: bold;"></span>Possible Solutions</span><br></span><br>Here we can have an examination of the priorities of the above problems, and proposed solutions.
<br><br>For each problem it should discuss the feasibility/cost of handling the problem in IDNAbis, versus the feasibility/cost of dealing with it at a different level (such as in a browser or in the registry). This is already done in many cases in issues-00. For example, the discussion of
<span>"8. The Ligature and Digraph Problem" does that, concluding that the problem cannot be feasibly handled in IDNAbis, and that it is more appropriate to handle in registries. But in many cases the discussion is lacking, and restructuring would make it clear where there are holes.
<br></span><br><span class="gmail_quote">Mark<br><br>On 2/2/07, <b class="gmail_sendername">John C Klensin</b> <<a href="mailto:klensin@jck.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">klensin@jck.com
</a>> wrote:</span></font><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<font size="2"><br><br>--On Friday, 02 February, 2007 14:29 -0800 Erik van der Poel<br><<a href="mailto:erikv@google.com" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">erikv@google.com</a>> wrote:
<br><br>> John,<br>><br>> As I read your idnabis-issues Internet Draft, I found that it
<br>> was<br>> difficult to decide what types of comments to make, since I<br>> didn't<br>> know what the goal of the draft was:<br>><br>> <a href="http://www.ietf.org/internet-drafts/draft-klensin-idnabis-issu" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
http://www.ietf.org/internet-drafts/draft-klensin-idnabis-issu</a><br>> es-00.txt<br><br><br>> Is this draft intended to be the 1st of a number of drafts<br>> that will<br>> eventually lead to an RFC about the issues and some of the
<br>> proposals?<br>> Or will they lead to an "IDNA Overview" RFC, similar to RFC<br>> 3490?<br><br>it is intended to see if we can agree on what we are talking<br>about and what is to be done, then to be split up into at least
<br>two pieces, one of which replaces 3490 and the other of which<br>provides background on the decisions. Since some of what is in<br>it has impact on nameprep and stringprep or their successors,<br>and the closely-related draft-alvestrand-idnabis-bidi has a
<br>different set of impacts, "at least" is important and other<br>organizations are possible.<br><br>> Also, it might be easier to make concrete comments if the<br>> draft was<br>> divided into sections corresponding to:
<br>><br>> (1) issues<br>> (2) solutions (or principles for solutions)<br><br>Watch for -01, probably next week.<br><br>> There may be some need for a section (0) on background. Also,<br>> section<br>> (2) could be put in a separate Internet Draft?
<br><br>That is the plan, but not until there is some greater consensus<br>about where we are going to end up. See above.<br><br>> To sum up, I believe it would be easier to comment on the<br>> draft if<br>> there were a clear distinction between perceived issues and
<br>> proposed solutions.<br><br>You have company, i.e., you are not the first to make that<br>comment. I work --and think and analyze proposals--<br>differently. I can't make any claim that my way is better,<br>
just different. If there are more people like you than there<br>are people like me, the split will occur sooner rather than<br>later (although probably not for -01).<br><br>regards,<br> john<br><br>_______________________________________________
<br>Idna-update mailing list<br><a href="mailto:Idna-update@alvestrand.no" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">Idna-update@alvestrand.no</a><br><a href="http://www.alvestrand.no/mailman/listinfo/idna-update" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
http://www.alvestrand.no/mailman/listinfo/idna-update
</a><br></font></blockquote></div><font size="2"><br><br clear="all"><br>-- <br>Mark
</font>