Re: [idn] Proposed suggestions from Asia Pacific Top LevelDomain meeting

[Mark.Andrews@nominum.com]

> >And thanks to Mark, I finally understood the difference between domain name
> >and host name. We havent even reach that defination yet...
> 
> So what is the difference?
> For me a host name is the name of a host while a domain name
> can be the name of a host or of many other things.

	Not bad for a first level answer.  For the second level you
	need to remember that host names have a MUCH more restricted
	syntax to domain names.

	Currently domain names have no restrictions on what is a legal
	character (8bit).  The only restrictions are total and label
	lengths.  Host names on the other hand are restricted to A-Z, 
	0-9, "-" and "." case insensitive.  "." is only allowed between
	labels.

	I keep listening to debates about what is / should be legal in a
	(international) domain name.  Restrictions on character sets and
	whether punctuation and control characters should be included. 
	Most of these arguements are really about what is / should be
	legal in a international host name.  I have made this plea once
	before.

	    Please be careful to use host name when you mean a host name.
	    Do not use domain name when you mean host name as it leads to
	    confusion.

	    Telnet uses host names.
	    Email uses host names or mail domains (these should both be
	    syntactically identical).
	    HTTP uses host names.
	    Traceroute uses host names.
	    hosts.equiv uses host names.
	    host.allow/host.deny uses host names.

	Personally I would like to see a similar distinction with IDNS.
	i.e. any character in a international domain name, a very
	restricted character set(s) in a international host name.
	
	Please remember that today we actually choose to use domain names
	that are not syntactically identical to hostnames so we can avoid
	accidental collisions with hostnames.  SRV records owner names are
	done this way.

	Mark
--
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