RE: [idn] Domain names and ASCII compatibility

[Karlsson Kent - keka <keka@im.se>]

> If we do an ASCII compatible encoding of domain names, we could do:
> 1) something like quoted-printable
> 2) something totally opaque.
> (Note: I will here give examples for host/e-mail compatible names as
>  they are probably most important).
>  
> 
> Examples:
>    Assume domain name: www.gås.net (gås has an a with ring 
> above in the middle)
>    
>    1): www.g-c3a5s-.net (using the mapping I suggested in my draft)

...moderately better than:

>    2): www.8wahdfhud.net
>        or when encoding all labels: b5a2d2d2d.8wahdfhud.i3aodfdvd

BUT, the method examplified in (1) is not a good idea for Latin-based
scripts, and it is just as opaque as the method examplified in (2)
for scripts that are not based on the Latin script.
       
>    E-mail: kåre.åkesson@gås.net
>    1): k-c3a5re.-c3a5kesson@g-c3a5s-.net
>    2): fh9ldfhtdfdobfhldfdududpdod@8wahdfhud.net
>        
> What is best?
> quoted-printable like mapping does allow ASCII characters to show
> as ASCII characters. Though for something like Japanese everything
> will be encoded.
> The opaque encodes all character including the ASCII characters,
> so it will be even more visible. Even ASCII only names can be
> encoded so even ASCII only users can see how it looks.
> And how are we going to get an e-mail displayed correctely
> (that is without encoded text) for the user?

I would venture that even after several decades such approches
will have decoding glitches.  Those WILL lead to complaints
from users that will see that as errors.

Please target a transition to pure UTF-8 (with fallback names
selected by a human, for use during the transition). E.g.
ESMTP/UTF8HEADINGS for e-mail, coupled with a name fall-back
lookup method for use when the fall-back name must be used, like
when UTF8HEADINGS is not supported at the receiving SMTP server.
HTTP seems to work as it is...  Other protocols may need to
be be upgraded to use the fall-back name lookup when talking
to non-upgraded instances of servers.  One could use the
"IP number name" as a fall-back to the fall-back, but that is
not user friendly either.  I don't dare venture into the details
of how this fall-back name service might be realised, nor
details on how existing protocols should be upgraded in an
orderly fashion.  I'm sure there are people on this list
that can do so; so I'm hoping for your help!

But please, let's not waste more time on TESes!

		Kind regards
		/kent k