Standardizing on IDNA 2003 in the URL Standard

Gervase Markham gerv at
Fri Aug 23 15:15:05 CEST 2013

On 23/08/13 11:19, Mark Davis ☕ wrote:
>  1. The TR46 non-letter support can be dropped in clients once the major
>     registries disallow non-IDNA2008 URLs. I say URLs, because the
>     registries need to not only disallow them in SLDs (eg http://☃.com),
>     they /also/ need to forbid their subregistries from having them in
>     Nth-level domains (that is, disallow http://☃
>     <> =
>     <>).

This is not my area of expertise, but I am not aware of a registry which
attempts to define by contract what their customers may or may not put
into the DNS "below" the domain they have purchased.

The way to make such domains not exist is for them to first not work in
browsers; I'm not sure we can do it the other way around.

>  2. The TR46 deviation character support can be dropped in clients once
>     the major registries that allow them provide a bundle or block
>     approach to labels that include them, so that new clients can be
>     guaranteed that URLs won't go to a different location than they
>     would under IDNA2003. The bundle/block needs to last while there are
>     a significant number of IDNA2003 clients out in the world. Because
>     newer browsers have automatic updates, this can be far faster than
>     it would have been a few years ago.

I would be greatly blessed if someone were to put together four lists,
one for each deviation character, of registries which allow that
character, their current approach to the compatibility risk (bundling,
blocking, nothing etc.), and their opinion (if they have one) on whether
or not IDNA2008 is the way to go.


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