Stupid U-label question [correction]
Frank Ellermann
hmdmhdfmhdjmzdtjmzdtzktdkztdjz at gmail.com
Wed Aug 20 13:46:55 CEST 2008
Tina Dam wrote:
> A domain name cannot begin with "xn--" unless it is an A-label.
> Your "u2" below is not an A-label as far as I can tell.
Yes, based on an IDNA2003 rule and the "--" rule in John's draft.
If he'd remove the "--" rule instead of replacing it by something
better xn--4caä could be an U-label, after all it's LDH plus one
perfectly PVALID umlauted a.
And if xn--4caä *would* be an U-label, then it *would* follow that
xn--xn--4ca-cxa is an A-label (and vice versa). Of course nobody
here wants this. An obscure corner case, maybe useful as example.
Frank
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