resource identifiers

[Ray Plante]

> >   <ResourceID>
> >     <AuthorityID>www.ncsa.uiuc.edu</AuthorityID>
> >     <ResourceKey>ADIL/SIA/targeted:95.DR.01.01.fits:wibble</ResourceKey>
> >   </ResourceID>
> > 
> > This also solves Roy's OAI problem. The worst string you'll get is:
> >   ivo://www.ncsa.uiuc.edu/ADIL/SIA/targeted:95.DR.01.01.fits:wibble

I applaud this move to get back to basics.  I would like to suggest 3 
refinements.  

1. Bring back the <RecordKey> as an optional component of the ID.

   The main reason for this has to do with using the ID to retrieve a 
   description from the registry.  A resource identified by only an 
   <AuthorityID> and a <ResourceKey> is guaranteed to resolve to a 
   description stored in a registry.  However, those that include a 
   <RecordKey> are not.  Nevertheless, if one has ResourceID that has 
   RecordKey component, one can still learn something about it by 
   retrieving the description of the resource it is a part of.  This would 
   be easier if the record component were separately tagged, rather than 
   parsing the ResourceKey (e.g. chopping at the first : ) which has to be 
   done outside of a standard XML parser.

   Thus,

   <ResourceID>
     <AuthorityID>www.ncsa.uiuc.edu</AuthorityID>
     <ResourceKey>ADIL/SIA/targeted</ResourceKey>
     <RecordKey>95.DR.01.01.fits:wibble</RecordKey>
   </ResourceID>

   (look familiar?  :-)

   I would add that contents of the RecordKey is entirely up to the 
   resource owner (apart from what from any character restrictions we 
   place; see below).

2. In the URI form, make # the delimiter between the ResourceKey and 
   the RecordKey.  

   This is more in the spirit of the #'s use in URL's in that it points to 
   a component of a resource.  And because of this connection to URLs, it 
   is less likely to be used as a non-special character within each of the 
   components.  (Another way to put this: people will more likely want to 
   use colon as a regular character, particularly in the RecordKey).

   (Thanks, Roy)

3. We should plan to spell out which are characters are legal and which 
   are not for each component.  The restrictions should be more stringent 
   on the AuthorityID and the ResourceKey due to their role in Registry 
   interfaces.  

Is this okay?

cheers,
Ray