[UA-discuss] Regular Expression

Andrew Sullivan ajs at anvilwalrusden.com
Wed Sep 13 05:50:23 UTC 2017

On Wed, Sep 13, 2017 at 12:01:07AM +0200, Chaals McCathie Nevile wrote:
> I would generally like validation to take place after punycode conversion.
> First because there are strings that match the regex bu not punycode
> constraints.

In an IDNA2008 world, there are no "Punycode constraints".  A U-label
corresponds to exactly one A-label, and conversely.  You can do it on
either side of the conversion divide.

Of course, if you're using the broken-for-years IDNA2003, you have a


Andrew Sullivan
ajs at anvilwalrusden.com

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