scope of SIA schema

[Markus Dolensky]

Hi Ray,

What's the scope of the SIA schema definition http://www.ivoa.net/xml/SIA/ ?

I simply assume that you were involved producing it and therefore my question 
to you:

In which context should it be used?
- When encoding SIA query mode response?
- As response to a registry query?

And, how about extending it to work also with SSA? The number of additional 
elements should be marginal.

The main issue I'm not clear about is the following, but I'm sure you and Doug 
have thought of it before:

The SIA query mode (and presumably SSA query mode) returns a VOTable that 
requires special client software to parse it. The question is whether we can 
avoid this in future by re-using things like the VOResource in the SIA/SSA 
query mode context. It seems, however, that the given SIA schema is weaving in 
what I would call registry-type components (VOResource, VODataService) PLUS SIA 
specific elements. The presence of the Schema suggests that SIA servers and 
clients need to support all of it(?)

Maybe I'm confusing things here, but anyway, the SIA and SSA docs that we are 
preparing for the upcoming NVO + interop meetings need to describe such 
dependencies.

Markus