Subject: Re: [apps-discuss] "organization's top level domain"

From: John C Klensin <[email-masked]>
Date: Thu, 09 Sep 2010 23:20:28 -0400

--On Thursday, September 09, 2010 13:17 -0400 Andrew Sullivan
<[email-masked]> wrote:

> On Thu, Sep 09, 2010 at 09:54:04AM -0700, Paul Hoffman wrote:
>> You're not going to like this, but -1 for a sad reason: the
>> principal domain name for Example Corp. is www.example.com,
>> not example.com.
>> 
> 
> Really?
> 
> We need to work out exactly what we mean by "domain name",
> then.

Andrew, I'm ok with ""organization's principal domain(s)",
subject to two qualifications:

	(1) Some example or explanation (along the line's of
	Paul's comments) appears.   And
	
	(2) You (or someone else) floats this by the
	DNSEXT/DNSOPS community and make sure that it doesn't
	either surprise or horrify them.  I appreciate your
	contributions, Peter's, and others to this conversation,
	but the about the last thing we need in the DNS
	terminology space is yet another term that is used
	differently in different communities.

As far as "exactly what we mean by 'domain name'" is concerned
and as you know, that is _not_ worked out and is a good example
of why we keep having these discussions.   I have seen that
term, sometimes used just interchangeably with "domain", widely
used to describe:
	
	* A label
	
	* An FQDN but not some appreciated name
	
	* An FQDN or an abbreviated name
	
	* The portion of an FQDN when the first (leftmost) label
	(and associated label-separating period when relevant)
	is removed.

In addition, it is unclear from some writing whether a "domain
name" must be in dot-separated-label form or whether it can also
refer to the internal, length-value form.

Unfortunately, part of the current discussion on the IETF list
about the terminology used in
draft-saintandre-tls-server-id-check and RFC 4985 strongly
illustrates the point.

There is reason to despair of getting the derived terms right if
the basic ones don't have well-defined definitions.

      john