Re: "International" email addresses [I18N-ACTION-374]

On 11/20/2014 8:37 AM, Phillips, Addison wrote:
> As Shawn and John note, a regex description of IDNA is probably 
> impossible. At best, such a regex would be an approximation.
The problem is not that it's impossible to do a rigorous description 
(essentially a regex) of the IDN rules for a given zone, but that the 
description varies along the tree, and that the knowledge of the rules 
that apply at each level is imperfect.

As I mentioned, there's an effort underway to define an XML format that 
allows one to capture any known descriptions in (essentially) a 
regex-like format expressed in XML that can be parsed and evaluated by a 
common engine.

If/when IANA's registry gets converted to this format, you should be 
able to do IDN validation, down to the second level at least, to any 
level of desired accuracy by querying the correct tables (or able to 
build approximate regexes with known degrees of accuracy - because you 
could then test them against any published full specifications).

Anyway, you find a draft here:


Received on Thursday, 20 November 2014 17:05:36 UTC