I believe that none of the current CONTEXTO characters are really required to be CONTEXTO, and all should be simply PVALID. I'd like to ask for a consensus call on this. There is a copy at <a href="http://www.macchiato.com/unicode/idna/exceptions/contexto-proposal">http://www.macchiato.com/unicode/idna/exceptions/contexto-proposal</a> in case emailers make this less readable.<br>
<br>Here are my recommendations in detail:<br>
<h2><a name="TOC-A.-HYPHEN"></a>A. HYPHEN</h2>
The rule on HYPHEN is unnecessary, since it is a requirement of the DNS
system anyway; this is completely redundant. So remove from Tables:
<ul><li><a href="http://tools.ietf.org/html/draft-ietf-idnabis-tables#appendix-A.1">http://tools.ietf.org/html/draft-ietf-idnabis-tables#appendix-A.1</a></li></ul>
<pre style="margin-left: 40px;"><span><h2><a name="appendix-A.1">Appendix A.1</a>. HYPHEN-MINUS</h2></span><br> Code point:<br> U+002D<br> Overview:<br> Must not appear at the beginning or end of a label.<br>
Lookup:<br> False<br> Rule Set:<br> True;<br> If FirstChar .eq. cp Then False;<br> If LastChar .eq. cp Then False;<br></pre>
<br>
<i>Note that in Protocol we have:<br></i>
<div style="margin-left: 40px;"><span>
<h5><a name="section-4.2.3.1">4.2.3.1</a>. Consecutive Hyphens</h5>
</span> The Unicode string MUST NOT contain "--" (two consecutive hyphens) in<br>
the third and fourth character positions.<br>
</div>
<br>
<i>The corresponding Lookup restriction is missing from Protocol and should be added.<br></i>
<h2><i><a name="TOC-B.-ARABIC-INDIC-DIGITS"></a></i>B. ARABIC-INDIC DIGITS</h2>
The rule on these overlaps with Bidi, and would be simpler and more
appropriately moved there, since these are all only of concern with
Bidi processing. So remove:<br>
<ul><li><a href="http://tools.ietf.org/html/draft-ietf-idnabis-tables#appendix-A.13">http://tools.ietf.org/html/draft-ietf-idnabis-tables#appendix-A.13</a></li><li><a href="http://tools.ietf.org/html/draft-ietf-idnabis-tables#appendix-A.14">http://tools.ietf.org/html/draft-ietf-idnabis-tables#appendix-A.14</a></li>
</ul>
And change BIDI from:<br>
<br>
<div style="margin-left: 40px;">5. If an EN is present, no AN may be present, and vice versa.<br>
</div>
<br>
To:<br>
<br>
<div style="margin-left: 40px;">5.
If an EN is present, no AN or EXTENDED ARABIC-INDIC digit
(U+0660..U+0669) may be present. If an AN is present, no EXTENDED
ARABIC-INDIC digit (U+0660..U+0669) may be present.<br>
</div>
<h2><a name="TOC-C.-Other-CONTEXTO"></a>C. Other CONTEXTO</h2>
<p>Remove the other CONTEXTO cases. These consist of only the following
6 characters, and there is no particular problem with making them all
simply PVALID in the Exceptions table.<br></p>
<table style="border-collapse: collapse;" border="1" cellspacing="0">
<tbody>
<tr>
<td><b>Code<br>
</b></td>
<td><b> </b></td>
<td><b>Name<br>
</b></td>
<td><b>Motivation?<br>
</b></td>
<td><b>My Comments<br>
</b></td>
</tr>
<tr>
<td><code><a href="http://unicode.org/cldr/utility/character.jsp?a=00B7" rel="nofollow">U+00B7</a></code></td>
<td style="text-align: center;"><font size="5"> · </font></td>
<td><font size="2">MIDDLE DOT</font></td>
<td><font size="5">a·<a href="http://b.us">b.us</a> <font size="2">vs</font><br>
<a href="http://a.b.us">a.b.us</a><br>
</font></td>
<td><font size="2">but different placement<br></font>
</td>
</tr>
<tr>
<td><code><a href="http://unicode.org/cldr/utility/character.jsp?a=0375" rel="nofollow">U+0375</a></code></td>
<td style="text-align: center;"><font size="5"> ͵ </font></td>
<td><font size="2">GREEK LOWER NUMERAL SIGN</font></td>
<td><font size="5">a͵<a href="http://b.us">b.us</a> </font><font size="5"><font size="2">vs</font></font><font size="5"><br>
a,<a href="http://b.us">b.us</a></font></td>
<td><font size="2">but , is illegal anyway</font></td>
</tr>
<tr>
<td><code><a href="http://unicode.org/cldr/utility/character.jsp?a=05F3" rel="nofollow">U+05F3</a></code></td>
<td style="text-align: center;"><font size="5"> ׳ </font></td>
<td><font size="2">HEBREW PUNCTUATION GERESH</font></td>
<td><font size="5">a׳<a href="http://b.us">b.us</a></font><font size="2"> vs</font><font size="5"><br>
a'<a href="http://b.us">b.us</a></font></td>
<td><font size="2">but ' is illegal anyway<br></font>
</td>
</tr>
<tr>
<td><code><a href="http://unicode.org/cldr/utility/character.jsp?a=05F4" rel="nofollow">U+05F4</a></code></td>
<td style="text-align: center;"><font size="5"> ״ </font></td>
<td><font size="2">HEBREW PUNCTUATION GERSHAYIM</font></td>
<td><font size="5">a״<a href="http://b.us">b.us</a></font><font size="2"> vs</font><br><font size="5">
a"<a href="http://b.us">b.us</a></font></td>
<td><font size="2">but " is illegal anyway</font></td>
</tr>
<tr>
<td><code><a href="http://unicode.org/cldr/utility/character.jsp?a=30FB" rel="nofollow">U+30FB</a></code></td>
<td style="text-align: center;"><font size="5"> ・ </font></td>
<td><font size="2">KATAKANA MIDDLE DOT</font></td>
<td style="white-space: nowrap;"><font size="5">a・<a href="http://b.us">b.us</a></font><font size="2"> vs</font><br><font size="5"><a href="http://a.b.us">a.b.us</a></font></td>
<td><font size="2">but different placement, width
</font></td>
</tr>
<tr>
<td><code><a href="http://unicode.org/cldr/utility/character.jsp?a=0483" rel="nofollow">U+0483</a></code></td>
<td style="text-align: center;"><font size="5"> ҃ </font></td>
<td><font size="2">COMBINING CYRILLIC TITLO</font></td>
<td><font size="5">a҃b
</font><font size="5">.us</font></td>
<td><font size="2">unclear motivation; but no worse than other combining marks. If
there is any problem with that, just make it DISALLOWED in the Exception section; it is archaic anyway.<br></font>
</td>
</tr>
</tbody>
</table>
<br><br><br><br><br><br>Mark<br>