Identifiers: Please read

[Ray Plante]

Hi all,

I'm a bit confounded by the amount of repetition going on on this list.  
I appreciate all comments; however, I plead to anyone that wishes to 
comment on this topic to PLEASE CAREFULLY READ the following:

  1.  The IVOA Identiers Working Draft:
      http://www.ivoa.net/internal/IVOA/IVOARegWp03/WD-ID-20030830.html

  2.  If you are interested in ADEC compatibility issues:
      http://ads.harvard.edu/www/dv/

At our Registry telecon this week, we agreed on the minor change 
to the IVOA Identiers Working Draft (IVOA ID WD) that can enable 
compatibility to the ADEC work.  I think there is sufficient desire among 
the ADEC participants to maintain compatibility in the development of 
their Data Resolver services.  

Some answers to recently posed questions:

> what is the advantage of having multiple resources
> registered under the same authority - other than abstract elegance?

An authority ID sets up a namespace.  Once you know the namespace is 
unique, you only have to worry about uniqueness within that namespace.  
You don't have to check uniqueness of a name within the namespace against 
names in other namespaces.  

Creating a namespace requires coordination at the global level.  The fewer 
namespaces you have, the less global coordination required.  

Authority IDs are only about defining a namespace and establishing an
owner of that namespace.  Requiring that it do anything else is outside
the scope of the ID WD.  If an organization wishes to create many
authority IDs for its own internal convenience (e.g. converting to URLs),
that is fine.  

> I was just thinking - why does the journal id have to be the resource
> identifier. 

It doesn't have to be; however, if they are different, data providers will 
find that they have to create two different, unrelated kinds of 
identifiers.  This could be greatly simplified for data providers (though 
you might not guess this from the discussion) if IDs used in journals were 
based on IVOA IDs.  In addition, it allows users to use IVOA-compatible 
registries to resolve the IDs found in journals.  (See 
http://www.ivoa.net/forum/registry/0595.htm.)

cheers,
Ray