Chris,<br><br><div class="gmail_quote">2009/7/29 Patrik Fältström <span dir="ltr"><<a href="mailto:patrik@frobbit.se">patrik@frobbit.se</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><div class="h5">On 28 jul 2009, at 16.50, Chris Wright wrote:<br>
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<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">CONTEXTO for HYPHEN-MINUS<br>
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* Is similar to the section in the protocol disallowing consecutive hyphens in the third and fourth position (4.2.3.1 of protocol document)</blockquote></div></div></blockquote><div><br></div><div> Agreed. It should be specified in the same place.</div>
<div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div class="h5"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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* Is applied to Unicode labels; the encoded label does not violate host name syntax</blockquote></div></div></blockquote><div><br></div><div>Agreed.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><div class="h5"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
* Has no context; the surrounding characters do not influence this test</blockquote></div></div></blockquote><div><br></div><div>While not dependent on surrounding characters, this test does hinge on the position of the character in the label.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div class="h5"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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I assume the rationale behind the prohibition of HYPHEN-MINUS at the beginning or end of a label is to carry across host name syntax restrictions into the Unicode label space. This appears to be attempting to achieve similar goals to section 4.2.3.1 in the protocol document by disallowing consecutive hyphens in the third and fourth positions. These two restrictions should appear in the same place.<br>
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To clear any confusion that may have arisen during limited discussion last week, the context rule is applied to the putative U-label, therefore the DNS and host name syntax restrictions do not apply (yet). Consider the label b[U+00FC]cher-. The output of this label through the punycode algorithm when appended with the ACE prefix gives gives xn--bcher--3ya. Note this label conforms to the host name syntax.<br>
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Thus for consistency, simplicity and clarity sake I propose the following:<br>
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In protocol change:<br>
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4.2.3.1. Consecutive Hyphens<br>
The Unicode string MUST NOT contain "--" (two consecutive hyphens) in the third and fourth character positions.<br>
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to<br>
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4.2.3.1. Hyphen Restrictions<br>
The Unicode string MUST NOT contain "--" (two consecutive hyphens) in the third and fourth character positions and MUST NOT start or end with a "-" (hyphen).<br>
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And then remove the context rule from the tables document and return hyphen to PVALID status as with all other LDH characters<br>
</blockquote></div></div></blockquote><div><br></div><div>Alternatively, have the two consecutive hyphens rule in the CONTEXTO as well.</div><div>There are pros and cons about having the rules in the protocol versus as a contextual rule. In any case, having it in the same place makes sense.</div>
<div><br></div><div>=wil</div></div>