Re: URN: vs alternatives

> In a parallel discussion going on over in the IETF mailing list at the 
> moment, Paul Vixie and other DNS gurus have pointed out that the DNS is 
> not a true directory service.  I think this is something that the URN design 
> should bear in mind.  I can see two scenarios here:
> 
> 1) You have a URN given to which you want to resolve to a single URC.  
> This is just like the DNS FQDN -> IP address mapping and so DNS may be 
> appropriate.

Yes, this is the scenario for which I would use DNS.

> 2) You want to know what URN for a certain document written by a
> particular person that has been registered by a particular organisation. 
> Now you could start guessing the DNS-like elements in the URN and in the
> early days when the namespace is small this will probably work most of the
> time.  

If you're assigning URNs and you want them to be persistent over several 
decades, you don't organize your URNs as a hierarchy of human-meaningful 
elements.  So DNS wouldn't even work in the short term for this case.

Even a directory may not make an effective resource discovery tool
for many subject areas.   Effective resource discovery often requires
tools which are tuned to a particular discipline or subject domain.

It might turn out that the most important function that URNs provide 
is to serve as a substrate for good resource discovery tools.

Keith