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punctuat</title></head><body>
<div>At 5:25 AM -0400 5/1/08, Vint Cerf wrote:</div>
<blockquote type="cite" cite>At the risk of prolonging this thread, I
am assuming that DISALLOWED is a condition that makes sense only for
an ASSIGNED character and that UNASSIGNED means the code point has not
been assigned any meaning or character.</blockquote>
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<div>That is not a good assumption. As Mark said yesterday:</div>
<div><br></div>
<div>At 6:59 PM -0700 4/30/08, Mark Davis wrote:</div>
<blockquote type="cite" cite>In Unicode, what we've been referring to
as "unassigned" (more precisely gc=Cn) means that a code
point (from 0 to 10FFFF) is not assigned *<i>to a character</i>*. The
code point may actually have properties even though it does not
represent a character: it might have bidi properties, block
properties, or, as in this case, be default-ignoreable or a
noncharacter.</blockquote>
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<div><br></div>
<blockquote type="cite" cite>This suggests that anything UNASSIGNED
should be rejected at the protocol level (no registration... no lookup
either?).</blockquote>
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<div>That could be true regardless of whether or not TUC had given the
gc=Cn properties.</div>
<div><br></div>
<blockquote type="cite" cite>Wouldn't this imply that a new revision
of UNICODE that ASSIGNS a previously UNASSIGNED character may require
reimplementation at protocol level of filtering since the previously
UNASSIGNED code point now has properties that might allow it to be
used in IDNs.</blockquote>
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<div>Now we fall into capitalization-in-specs issues.</div>
<div><br></div>
<div>- If TUC moves a character out of gc=Cn (that is, they assign a
code point to a character), and that character had the IDNA property
of UNASSIGNED, TUC's action would the change IDNA property from
UNASSIGNED to something else.</div>
<div><br></div>
<div>- If TUC moves a character out of gc=Cn (that is, they assign a
code point to a character), and that character had the IDNA property
other than UNASSIGNED, TUC's action might or might not change the IDNA
property.</div>
<div><br></div>
<div>Neither would "require reimplementation at protocol level of
filtering". The first would, and the second might, change the
table used for filtering.</div>
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