Re: [idn] IDNs and email

[Mark.Andrews@nominum.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.

	I do.  The most common one is called SMTP (case insensitive).  Go
	read RFC 821 and see what is currently legal as a mail domain.

> 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.
> 

	RFC 952 + RFC 1123 defines what is currently legal in a hostname.

>     Andy
> 
--
Mark Andrews, Nominum Inc. / Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews@nominum.com