In the xerces SAX impl, they add an external
schema property. That would be nice to have it
because you can easily test the same XML with
Logged In: YES
The right way to do Schemas (not just W3C ones) with SAX
is as a clean layer. For example, as a filter that
recognizes features such as this, and includes handlers
that are used to report the PSVI data.
Such properties are inappropriate for the SAX core, and
shouldn't be defined apart from the overall specification
of a SAX Schema Layer.
So I'm rejecting this RFE, with the understanding that
it might get revisited as part of a
properly layered schema framework, if someone starts
such work. One start might be the ISO RELAX framework
(see the "links" page), which also includes partial
support for W3C schemas.