multiple capabilities of the same kind

[Ray Plante]

Hi Doug,

On Fri, 15 Feb 2008, Doug Tody wrote:
> How do we handle a service which supports two versions of the same
> interface - are these separate capability elements as well?  I suspect
> so, in which case having multiple capabilities of the same basic type
> is probably unavoidable.

There is an explicit mechanism for this.  In the case in which the two 
versions both use the same capability type and the capability metadata are 
the same, then one can list multiple <interface> elements, each with a 
different "version" attribute.

It may be that version 2.0 of a protocol may define a different or 
extended set of capability metedata.  In this case, the new version would 
define a new capability type.  Thus, the two versions would be 
distinguished by 2 different capability elements.

The ambiguous case that result in the same difficulty that Paul referred 
to is if the two versions can be described with the same capability type 
but the values of the capability metadata are different.  At the moment, 
the best way to handle this case is to register these as separate 
resources.

cheers,
Ray