Subject: [urn] continued validity of URNs (CREF12)

From: Peter Saint-Andre - &yet <[email-masked]>
Date: Wed, 11 Mar 2015 20:38:09 -0600

Section 6.1 states:

    3.  Commitment to not reassigning existing names and to allowing old
        names to continue to be valid, even if the owners or assignees of
        those names are no longer members or customers of that
        organization.  With regard to URN resolution [RFC2276], this does
        not mean that there needs to be resolution of such names, only
        that the names will not resolve to false or stale information.

CREF12 poses a question for the WG about how we should handle this 
question from Henry Thompson:

    "Really?  If a piece of retrievable metadata for some URN is the
    name and (postal) address of the publisher of whatever it
    identifies, and they've gone out of business, that metadata is
    necessarily stale, isn't it?"

First, I'm not sure what we mean by "retrievable metadata for some URN" 
here because I think it confuses the issue, which is about the URNs 
themselves.

Let's say that someone defines a urn:publisher namespace and that a 
publisher "Leblanc Press" is identified by urn:publisher:24601. The rule 
about not reassigning the URN doesn't have anything to do with the 
address of Leblanc Press, the continued business operations of Leblanc 
Press, or any other metadata associated with Leblanc Press. All it says 
is "don't reassign urn:publisher:24601 to, say, Madeleine Press". The 
URN always refers to Leblanc Press, even if that "resource" has been out 
of business for 1000 years.

If some clarifying text is in order here, let the authors know.

Peter

-- 
Peter Saint-Andre
https://andyet.com/

---

From: [email-masked] (Henry S. Thompson)
Date: Thu, 19 Mar 2015 12:38:46 +0000

Peter Saint-Andre - &yet writes:

> First, I'm not sure what we mean by "retrievable metadata for some
> URN" here because I think it confuses the issue, which is about the
> URNs themselves.
>
> publisher "Leblanc Press" is identified by urn:publisher:24601. The
> rule about not reassigning the URN doesn't have anything to do with
> the address of Leblanc Press, the continued business operations of
> Leblanc Press, or any other metadata associated with Leblanc
> Press. All it says is "don't reassign urn:publisher:24601 to, say,
> Madeleine Press". The URN always refers to Leblanc Press, even if that
> "resource" has been out of business for 1000 years.
>

I should have been more careful to make clear that my comment was
about the second sentence, that is, the one about resolution.  To
continue with your example, suppose urn:publisher URNs have a
resolver, and that resolver, when queried wrt urn:publisher:24601,
supplies some form of information describing Leblanc Press, giving its
address and company number, as of the last year of its existence.  500
years from now that information, although true (provided it is clearly
date-constrained), is certainly stale.

The minimum necessary to declare victory, in my view, is just to
remove the final clause, i.e. so the sentence reads

   With regard to URN resolution [RFC2276], this does not mean that
   there needs to be resolution of such names.

In my view requiring the human-interpretable content of HTTP messages
to be true is way outside the remit of a protocol standard :-).

ht
-- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
      10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
                Fax: (44) 131 650-4587, e-mail: [email-masked]
                       URL: http://www.ltg.ed.ac.uk/~ht/
 [mail from me _always_ has a .sig like this -- mail without it is forged spam]

---

From: Peter Saint-Andre - &yet <[email-masked]>
Date: Thu, 19 Mar 2015 07:35:01 -0600

On 3/19/15 6:38 AM, Henry S. Thompson wrote:
> about the second sentence, that is, the one about resolution.

Ah, that helps.

> To

Agreed.

I would prefer to say as little as possible (if anything) in this 
specification about URN resolution.

> to be true is way outside the remit of a protocol standard :-).

Indeed!

Peter

-- 
Peter Saint-Andre
https://andyet.com/

---

From: Peter Saint-Andre - &yet <[email-masked]>
Date: Mon, 23 Mar 2015 21:13:47 -0600

> specification about URN resolution.

I propose that we remove this sentence from Section 6.1:

        With regard to URN resolution [RFC2276], this does not
        mean that there needs to be resolution of such names, only that
        the names will not resolve to false or stale information.

If RFC2276 is updated or replaced, that specification can say something 
about the matter.

Peter

-- 
Peter Saint-Andre
https://andyet.com/