RE: [idn] IDNs and email

[Andrew Draper <ADRAPER@altera.com>]

Paul Hoffman / IMC wrote:
> At 09:15 AM 2/15/00 -0800, ned.freed@innosoft.com wrote:
> > > | If an encoding is used which is not mapped into ASCII then there
SHOULD
> > > | be an ASCII-only representation of each IDN, and there MUST be a way
for
> > > | a program to find the ASCII-only representation (or lack of it) for
an
> > > | IDN.
> >
> >Nicely put. I agree completely.
> 
> There are two issues here: ASCII and DNS-compatible names.  Protocols like

> SMTP and PKIX require ASCII, but there may be protocols that define 
> DNS-strings to single-case letters plus digits plus '-' only. If such 
> protocols exist (and I don't know that they do, but I wouldn't be 
> surprised), do we want to accommodate those as well?

I don't know of any such protocols but also suspect they exist.  Do we need
to
find an example before we start to design around them?

I meant a DNS-compatible name but couldn't think of a clear way to say what
I
meant.  What about using hostname-charset instead of ASCII-only?  This
changes
the requirement to:

| If an encoding is used which is not mapped into the hostname charset then
| there SHOULD be a hostname-charset representation of each IDN, and there
| MUST be a way for a program to find the hostname-charset representation
| (or lack of it) for an IDN.

There should probably be a definition of hostname-charset somewhere as well:

| hostname-charset.  This is the character set which is legal in legacy
domain
| names (before IDN).  It consists of the ASCII characters A-Z (case
insensitive
| matching), the digits 0-9 and the hyphen.  

Of course if someone can find a reference instead then that would be better.

    Andy