question about interface/operation/@style and interface/@styleDefault

With the decision to support multiple type systems yesterday, I'd
like to clarify how it affects @style. The current wording for
@style is specific to schema languages which define elements:

=====
If the {style} property of an Interface Operation component has a
value then that value (a URI) implies the rules that were used
to define the {message} properties of all {message reference}s 
within that component. Note that the property MAY not have any
value. If this property has a given value, then the rules 
implied by that value (such as rules that govern the schemas)
MUST be followed or it is an error.
=====

(Replace {message} by {element} when u read the above.)

Do we want to generalize this to say something like "{element}
or other property which defines the content of the message"?
It seems to me that we should as otherwise we'd be short-changing
the support for multiple schema languages.

IMO it is still fine for the *RPC style* to be defined specifically
for XML Schema (as it is now). 

Comments?

Sanjiva.