Re: [idn] Adding "optional" characters in draft-ietf-idn-nameprep

[Keith Moore <moore@cs.utk.edu>]

> > machines need to know how to translate IDNs from whatever
> > encoding they use into unicode/10646 (for queries) and back
> > (for address lookups).
> >
> 
> That is very reasonable... why then is it not a good idea to tag the
> encoding as we have suggested in a standard and easily recognizable way?

if you always use unicode on the wire, there's no need for a tag.
systems that have to support multiple encodings (or even the
possibility of multiple encodings) are far more complex than
single-encoding systems.

> > >  but I thought
> > > there were suggestions to rejected some characters in the DNS such as
> > > symbols?
> >
> > perhaps, but this would be as a matter of policy, rather than as a
> > constraint that is wired into the IDN protocol.
> 
> A matter of policy for respective registries?  

perhaps, but ideally, no.  or at least, not as a solution to the 
transcription problem.  the last thing we need is for registries
to compete against one another on the basis of which one accepts
which characters.

registries will of course continue to have some policy about what
kinds of names are accepted, so one cannot rule out that some 
registries will be more restrictive than others about which
characters are allowed in names.

Keith