[versioning-3] Re: Vocabularies issues

[Norman Gray]

Rick, hello.

On 2008 Feb 4, at 11:54, Frederic Hessman wrote:

> 3.  Versioning
> 	___ explicit in namespace (e.g. http://myvocab.org/myvocab_v1.1#mytoken)
> 	___ hidden, like in Dublin Core (e.g. http://myvocab.org/myvocab/#mytoken)
> 	_X_ both, a new option: the hidden version is the latest, but  
> really points to explicitly labeled version, so that old versions  
> remain accessible.
[...]
> My vote on issue 3 is cheating, since Norman didn't list the third  
> option:  hidden versioning is convenient for most users as long as  
> there is a mechanism for determining what version one has read in  
> the past (to see if anything has changed)

If I'm correctly understanding what your 'both' option is, then I  
think that's what Dublic Core does.  If you dereference the  
versionless DC terms namespace <http://purl.org/dc/terms/> then what  
you get is a redirection to (versioned) <http://dublincore.org/2008/01/14/dcterms.rdf 
 >.  This was option 1 in <http://www.ivoa.net/forum/semantics/0801/0660.htm 
 >.  This is what you mean, yes?

In this option, clients do any required reasoning with a versioned  
namespace, and the published/publicised URL is unversioned, and really  
only used for discovery.  This sounds plausible to me.  Is this an  
actual Best Practice, does anyone know?  Does it have downsides?

All the best,

Norman


-- 
Norman Gray  :  http://nxg.me.uk
eurovotech.org  :  University of Leicester