[UA-discuss] [UA-EAI] Issue needs discussion and closure

[Martin J. Dürst]

Hello Mark, others,

On 2018/03/12 03:43, Mark Svancarek via UA-EAI wrote:
> Here is my reasoning:
> 
> We forbid script mixing in the root for well-understood reasons.  A few exceptions were carved out, though.
> The same thought process could be applied to second level and below.  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.
> The local part is even less restricted than the 2LD.  But again, I think the same benefits to the users apply.

For local parts, I think it depends a lot on the size of the 'operation'.

The problem is easy to handle on a case-by-case base for e.g. an 
University lab that's handling out email addresses to its members. 
Script mixtures may not be a problem at all, because it's easy to avoid 
conflicts and confusions.

On the other end of the spectrum (big web mail providers and such), 
strict rules will have the benefit that they eliminate a lot of problems 
while keeping almost everything automatic.

> Given the perceived benefits, is there any concern about defining a good practice on creation of local parts by a mail service provider?  (It would be written more clearly than below...)

With regards to script mixing, the Japanese case has already been 
mentioned. Also, the main arguments against script mixing are visual 
confusion across scripts and bidirectionality issues. 
Latin/Greek/Cyrillic is the main case; there may be some well-known 
cases across Indic scripts, too, but for any two scripts taken at 
random, the chance of confusability is pretty low. Bidirectionality 
considerations essentially split the scripts into two, but will still 
allow e.g. mixing Arabic and Hebrew.

Mixing arbitrary scripts in LHS probably doesn't have too much of a need 
anyway in the first place, but that doesn't mean it should be totally 
discouraged when it's not harmful.

Regards,   Martin.

> -----Original Message-----
> From: Tan Tanaka, Dennis [mailto:dtantanaka at verisign.com]
> Sent: Sunday, March 11, 2018 12:49 PM
> To: Mark Svancarek <marksv at microsoft.com>
> Cc: Ajay Data <ajay at data.in>; ua-discuss at icann.org
> Subject: Re: [UA-discuss] Issue needs discussion and closure
> 
> 
>> On Mar 11, 2018, at 9:00 AM, Mark Svancarek via UA-discuss <ua-discuss at icann.org> wrote:
>>
>> We should recognize that the local part rules are very permissive and therefore this should be an ALLOWED case per the spec.  But I vote that UASG declare it as a NOT RECOMMENDED case EXCEPT for script combinations which are already allowed to be mixed in the root zone.
> 
> I would stop at the first part and add that each mail admin set its own rules as far as mailbox names. The second part is troublesome as it mixes mailbox names with the (dns) root zone. I don't see the need for a connection. Am I missing something?
> 
> -Dennis
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