2-stage identifier resolution

[Ray Plante]

Hey Roy,

This looks good to me.  

On Wed, 19 Apr 2006, Roy Williams wrote:
> For these reasons, VOEvent packets will often contain VO identifiers, 
> defined and discussed in [16].  These take the general form 
> "ivo://authorityID/resourceID#localID", 

If this statement were intended to be, say, part of a standards 
document--that is, where we might quibble about precision, I would point 
out that technically the bit following # is not part of a VO identifier.  
More precise wording would be...

 "...will often contain identifiers that build on the IVOA standard 
 identifier, defined and discussed in [16].  The packet identifiers take 
 the general form "ivo://authorityID/resourceID#localID",..."

However, if this is part of most any other document, it's probably not 
worth clouding the issue over such a detail, so it's fine as is.

> But if there is no # symbol, then it can be done in one call.

This is an intriguing idea.  This would imply that you would be able to 
use the registry interface to resolve, harvest, and/or search for events.  
All this is possible in principle (though you would have to support a 
VOEvent format that is based on VOResource).  

In practice though, we probably wouldn't integrate VOEvent records into 
our full registries, as these would clearly be too fine grained.  So I'm 
not sure how useful this would be.  

cheers,
Ray