On Thu, 12 Jan 2017, Tim Ruehsen wrote:

>> Can you elaborate on some specific incompatibilties you're aware of? Aren't
>> the problem mostly that there are still clients using IDNA2003 and not so
>> much in the other end?
>
> I just can tell you "rumors" that I heard/read.
> - Some registries still use IDNA2003 (unsure, read it on Twitter a while ago)
> - IDNs in TLS certificates are still encoded with IDNA2003 (likely)

Okay, so we can suspect that there's still some IDNA2003 traces left out
there, and at the same time we know that the .de TLD *requires* IDNA2008 so we
know for sure that not using it will break .de domains. A fairly big and well
populated TLD.

IDN2_TRANSITIONAL feels like the way to go.

-- 
  / daniel.haxx.se
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