[UA-discuss] Mixing between RTL and LTR scripts

[John Levine]

> Also I don't know how you disallow script mixing for domain names. IDNA is 
> label by label. The DNS is distributed, so there's no way to prevent mixing, 
> is there?

As far as I am aware, the only place where script rules are enforced in 
the DNS are at the top level, where ICANN has its process, and in TLDs 
that have rules about what 2LDs or 3LDs they'll register.  Other than 
that, DNS operators can publish anything they can punycode, which is any 
UTF-8 including punctuation and emojis.

In EAI e-mail addresses, the local part before the @ sign can be any 
printable UTF-8, so mixed direction text is valid even though it's a bad 
idea.

R's,
John

> ----------
> On May 4, 2018 05:36:02 "John Levine" <john.levine at standcore.com> wrote:
>
>>>                 I hope you all doing well, after back to TF-AIDN "Task
>>>                 Force Of Arabic IDNs", I got the following regards to
>>>                 mixing LTR and RTL texts within the same label.
>>>  -          Mixing between different scripts is not allowed for domain
>>>  names and email addresses
>>>  -          Numbers at the middle or at the end of the RTL domain name is
>>>  allowed.
>>>
>>>  To be away from the display issues we get if we mix RTL and LTR code
>>>  points in the same labels.
>>
>>  Thanks.  I think this clarifies the point that we have no advice on
>>  displaying e-mail addresses, since mailboxes are not domain names and are
>>  not labels and are not subject to IDNA2008.

Regards,
John Levine, john.levine at standcore.com
Standcore LLC