[UA-discuss] Issue needs discussion and closure

[Andrew Sullivan]

On Sun, Mar 11, 2018 at 06:43:34PM +0000, Mark Svancarek via UA-discuss wrote:
> Here is my reasoning:
> 
> We forbid script mixing in the root for well-understood reasons.

But we don't forbid script mixing in the root.  The LGR effort is
busily trying to set the correct rules for this, but the root already
has more than one script, and there are defintiely potential labels
corresponding to Japanese words that require script mixing.  The rules
are actually aimed at prohibiting mixing of _writing systems_, which
in the last go round was approximated as "script".

> The same thought process could be applied to second level and below.

But this gets harder the lower in the tree you go, because there is no
authority to enforce it.  Moreover, things that would be a very bad
idea for the root, such as (say) Egyptian hieroglyphs, would be just
fine at other layers of the DNS.  And there's the problem of different
scripts in different labels, which is a permanent and unresolvable
problem because of the nature of the DNS.

> It's not an obligation, but the benefits to the user are the same and I think it is safe to say that it's a good practice to apply those same restrictions and exemptions to any label in a domain name.

What is certainly safe to say is that you should not create
identifiers where you don't understand what the implications are.  

Best regards,

A
-- 
Andrew Sullivan
ajs at anvilwalrusden.com