RE: [URN] WG last call: URN Namespace Definition Mechanisms

["Larry Masinter" <[e-mail]>]

> The draft even clearly mentions the possibility of subdividing  
> (partitioning) namespaces.

draft-ietf-urn-nid-req-06.txt clearly mentions the possibility
of subdividing the name space in order to delegate the assignment
of uniqueness, as happens, for example, with ISBN numbers, where
each publisher is delegated the authority of keeping their part
of the name space unique.

However, in the case of urn:us:ssn:001-101-4452 and
urn:us:ca:license:7URN123, this is not merely a delegation
for the purpose of uniqueness, but a separation of the namespace
into subspaces which will differ for every attribute in the
template given in draft-ietf-urn-nid-req-06.txt.

If you go through the fields in the draft:
   Registration Information
       Suppose that california changes their license plate registration
       mechanism in 2002, while the US changes social security numbers
       in 2014. The versioning of the name spaces would occur at
       different times.
   Declared registrant of the namespace
       This would migrate
   Declaration of syntactic structure
       Unlike the ISBN example where there is a uniform syntactic structure,
       the structure of license plates and social security numbers are
       different. Each "subnamespace" is likely to have a different
       syntactic structure.
   Relevant ancillary documentation
       The documentation for describing the rules of license plate
       numbers and vanity plates are different documents than those
       that describe the assignment of social security numbers.
   Identifier uniqueness considerations
       These are likely to differ for each subnamespace.


It would seem that these can't be easily handled by  having a 
country-code URN namespace then having the country parcel it out
for country-unique spaces. I could imagine reserving the names
"xx-<blah>" for country xx, so that "us-ssn" would be recommended
over "ssn" to distinguish it from "dk-ssn", but I'd think that
each of these should be registered separately.

Larry