Re: uri, urn and info

On Fri, 2003-10-10 at 15:57, Ray Denenberg, Library of Congress wrote:
> From: "Hammond, Tony (ELSLON)" <T.Hammond@elsevier.com>
> Assuming so, that seems to break down to two requirements:
> (a) an identifier, once assigned (within a namespace), won't ever be
> assigned again (within that namespace); and
> (b) it will be bound to the resource even beyond the lifetime of the
> resource.
> 
> Clearly the identifiers we're talking about meet requirement (a).   But is
> (b) a meaningful requirement?
> 
> An LCCN certainly meets requirement (a).  But (b)?  An LCCN identifies a
> bibliographic record.  If that bibliographic record is deleted, what does it
> mean to fulfill requirement (b)? That when someone tries to follow that
> LCCN, they would be informed "LCCN 99-123456 used to be assigned to the
> bibliographic record for book xyz, but that record no longer exists"?   If
> they get "record not found" then the identifer is not persistent?

No. It simply means the Resource identified by that identifier isn't
persistent. Let's say that meta data record is deleted but then restored
at a latter date once an archive is setup. Does that mean the identifier
somehow winked out of existence but then came back 'alive' when some
representation of that resource connected itself back up to the network?
No. The identifier is always bound to what it was bound to originally
regardless of whether or not some network accessible representation of
that resource is available on any network or still exists in any
physical form. For example, I might assign an identifier to Abraham
Lincoln. Just because he's no longer around in any corporeal form
doesn't mean the identifier assigned to him is invalid or somehow
disappears....

-MM

Received on Friday, 10 October 2003 16:02:48 UTC