Re: TB16 Re: Comments on arch doc draft

I think the proposed recommendation that namespaces be dereferenceable is 
fine as long as it's in the form of a SHOULD, as opposed to MUST. 

One can surely imagine namespaces for which dereferenceability is not an 
issue.  As one simple example:  one could imagine very transient 
namespaces used in one or two dynamically created documents, perhaps used 
within a single system for internal purposes, and never used again.   In 
fact, a UUID: URI (which in many systems behaves as a URN and is not 
easily dereferenced) seems like a quite appropriate scheme for such 
namespace names.  Thus, SHOULD seems fine; MUST would be a serious mistake 
IMO.  Thank you.

Noah Mendelsohn                              Voice: 1-617-693-4036
IBM Corporation                                Fax: 1-617-693-8676
One Rogers Street
Cambridge, MA 02142

Tim Berners-Lee <>
Sent by:
07/01/2002 05:51 PM

        To:     "Dare Obasanjo" <>
        cc:     "Ian B. Jacobs" <>, "Tim Bray" <>, 
<>, (bcc: Noah Mendelsohn/Cambridge/IBM)
        Subject:        Re: TB16 Re: Comments on arch doc draft

Yes. URNs are not dereferencable and therefore should not be used for
namespace names.  It deprives someone who does not know the name
of the ability to look it up and get useful information about it.
It especially deprives a machine of that possibility.

Tim BL

On Monday, July 1, 2002, at 04:48 PM, Dare Obasanjo wrote:

Dare Obasanjo wrote:
> Since URIs comprise the set of URNs as well as URLs I'm not sure exactly
> how one can state that namespace names should be dereferencable if there
> is no uniform mechanism for dereferencing URNs nor is it clear whether
> they were originally designed to be dereferenced.
> --
> In the field of observation, chance favors only the prepared minds..
> This posting is provided "AS IS" with no warranties, and confers no
> rights.

Received on Monday, 1 July 2002 18:19:50 UTC