illegal/unrecommended use of IVOA identifiers

[Ray Plante]

Hi John,

On Fri, 17 Nov 2006, John Taylor wrote:
> First up, apologies for the delay in replying to this. There is A Reason 
> behind the choice of ivoids as messages.  They're meant to be unique, so 
> using a URI seems to be reasonable.  Why a registry URI?  Well, we think that 
> there could be a benefit in registering the messages as separate resources.

I believe you can do all of this with the syntax I recommended, e.g.

    ivo://votech.org/plastic#info/getIVORN

That is, you would be able to:
    o  search the registry to discover the meaning of this message
    o  search the registry for applications that support this message
    o  have a tool interogate the registry to build a GUI for the message

These capabilities would rely on:
    o  there being registered a Plastic resource, of type "Standard" where
       the messages are defined.
    o  there being tools that register their support for the messages
       (say as capabilities).

The motivation for this alternative is to preserve two principles consider 
very important:
    o  that you can, via a registry, dereference an IVO ID to a
       description.
    o  that the registry focus on course-grained resources, so that
         + we control the rate of growth of the registry, thereby
           controling the performance and maintanence costs
         + we not confuse end users with a vast number of resources that
           are rarely of interest to them
         + we not replicate the information content that is better managed
           by local providers and accessed through 2ndary services (e.g.
           SIA)  (This point is item is less relevent to the plastic
           issue.)

hope this clarifies things,
Ray