Subject: [urn] perhaps a different perspective on URNs?

From: "Larry Masinter" <[email-masked]>
Date: Sun, 6 Jun 2010 11:42:23 -0700

I wouldn't mind helping with some of the history
and current issues.

http://masinter.blogspot.com/2010/03/resources-are-angels-urls-are-pin
s.html
http://www.w3.org/Bugs/Public/show_bug.cgi?id=8116

My recent thinking on URNs is that the properties of
"location-independent" and "persistent" are not (or should
not be) the key distinguishing feature of URNs vs any
other kind of URI.

Rather, what makes sense to me best is to note that URNs
are primarily distinguished by the reliance on an authority --
some organization, consortium, informal alliance, collective --
which maintains the correspondence between URNs and the resources
they name.

These authorities offer or promise different kinds of service
guarantees for being able to resolve the URN than might be
available using traditional internet methods that rely on DNS
and its administration.

Observation:
 urn:uuid was a mistake, but most of the other URN namespaces
 seem to fit this definition quite well.

Larry

---

From: Alfred Hönes <[email-masked]>
Date: Tue, 8 Jun 2010 20:58:12 +0200 (MESZ)

Larry Masinter wrote:

> http://masinter.blogspot.com/2010/03/resources-are-angels-urls-are-pins.html

Thanks for these pointers.

However, I'm not sure this discussion helps much wrt the primary
goals we have of arriving at basic documents on URNs that can be
advanced on the maturity ladder of the IETF Standards Track.

> available using traditional internet methods that rely on DNS

Interesting note.
See more thoughts and comments below.

>  seem to fit this definition quite well.

So you are saying that's precisely why the 'geo' URI scheme
(RFC 5870, just published) didn't make it as a URN namespace?

Back to the main remark:

However, it seems important to observe that "persistent" and
"reliance on a renowned authority" (attribute added, tempted
to prefix "well-" as well!) are very closely related.

The proposed registration template for the 'urn' URI scheme
I have drafted in Section 7.1 of draft-ah-rfc2141bis-urn
contains the following fundamental clause:

   URI scheme semantics:

      'urn' URIs, known as Universal Resource Names (URNs), serve as
      persistent, location-independent, resource identifiers for
      concrete and abstract objects that have network accessible
      instances and/or metadata.

      URNs are structured hierarchically into URN Namespaces, the
      management of which is delegated to namespace-specific
      authorities.  Each such URN namespace is founded in an independent
      specification and registered with IANA, following the guidelines
      and procedures of BCP 66 (at the time of this registration: RFC
      3406).

Doesn't that clause already capture at least some smell of your
considerations?  Should we add in the 2nd paragraph:
      authorities _that maintain the uniqueness and persistence of these
      identifiers_.  [...]
?

Please also note the shift of emphasis from the opalescent term
"resource" to "concrete and abstract objects".  The former has been
retained to remain close to RFC 2141 (et al.), but eventually it could
be dropped entirely from this clause.

  Alfred.