On 03/28/2015 04:42 AM, Dave Cridland wrote:
I agree that urn registration is a pain, and it lacks any domain based
ad hoc usage. Both those are bad; Google, for example, use both an
unregistered scheme of google, and a urn namespace urn:google. The
former they could in principle register; but the latter they couldn't
due to the draconian rules.
One of the many things that motivated creation of URNs was to avoid the
mess that resulted when DNS names were taken away from their owners, or
when resources had to be rehosted elsewhere (say when an organization
split or some of its activity moved to another organization), thus
invalidating the URLs that had been assigned to those resources. URNs
are supposed to be long-term stable names in ways that it's difficult to
assure for DNS-based URLs.
At one time people did kick around the notion of combining a DNS name
with a date, to avoid that problem. That would allow URNs with that
name to continue to be valid, but depending on that the DNS name for
resolution would still be problematic. But that still has the
potential for thorny trademark-related issues. And there have at
various times also been attempts to threaten the uniqueness of DNS
names, e.g. by creating alternate DNS roots, so making URNs that relied
on DNS names seemed dubious for that reason also. Bottom line:
embedding DNS names in URNs seems like a bad idea.
(One thing that handles and DOIs got right, and I wish we had done with
URNs, was making their equivalent of "name space identifier" completely
devoid of any company name or trademark.)
Keith