RE: [idn] Unicode tagging

[Andrew Draper <ADRAPER@altera.com>]

Keith Moore wrote:
> the problem isn't what you do with them in DNS; the problem crops
> up when either a human being or a computer program tries to copy them 
> to email and finds that the email system either (a) (today) doesn't 
> support non-ASCII email addresses or (eventually) (b) doesn't use the 
> same encoding for non-ASCII email addresses.

I don't think we're in disagreement over point a.  I think most
administrators will understand "It is possible to encode the LHS of an email
address in the DNS but there's no point until the email system supports
them".

I disagree with b though.  If the email system chooses a different base36
style encoding then computers copying email addresses into DNS (to look up
keys) need to understand both and use the appropriate encoding at a
particular time.  Ordinary users should not see base36 encodings of anything
(especially SOA records).  Administrators should understand the difference. 

I think choosing a different scheme for email would be a bad idea though
since  users and administrators will get confused when an email address is
sdfsdkfs@example.com for email and kdkfe4p.example.com when put into a zone
file.

Using the email encoding scheme within DNS would be a bad idea since there
will be collisions between the email encoding and the IDN encoding (for
example if the IDN encoding of thecafe.example.com turns out to be
kdkfe4p.example.com and collides with the email address above)

Regards,

    Andy