Stability of valid IDN labels

Andrew Sullivan ajs at
Tue Apr 22 16:28:57 CEST 2008

On Tue, Apr 22, 2008 at 07:15:41AM +0200, Patrik Fältström wrote:
> Personally I see it much much more rigid. Once a character have been 
> assigned in Unicode it will by definition get a derived property value due 
> to the algorithms defined in the IDNA200X documents. That value can never 
> change.

I'm probably about to flaunt my ignorance, but I thought I remembered
reading some while ago (on this list, I think) that the tables in the
Unicode standards are the actually normative part; that once a table
has been issued in a version, it will never change; but that, if there
is an error in a table, that error _might_ be corrected in a future

If I understood that correctly, then it seems possible that the
Unicode classification of a code point could get changed between
Unicode versions, and therefore that the derived property could
change, too.  (Actually, I thought it was this exact corner case that
we were worrying about in this discussion.  Maybe I'm fretting about
something that can't happen?)


Andrew Sullivan
ajs at
+1 503 667 4564 x104

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