1. XPath is not schema aware and it will match only elements by the same
name as in the selector. Hence you will have to provide a selector that
specifically matches "Shirt" and "Shoes"

2. Processors that perform schema validation according to W3C XML Schema
should be aware of substitutionGroups and you shouldnt need to perform any
special processing to handle them.

Thanks,
Priya

"David Blickstein" <db@h...> wrote in message
news:q7e3e.2746$K%2.1791@n......
> Suppose I have an XML Schema that contains a keyref that is part of a
> substitution group.
>
> Let's say I have a "Product" element that contains a field ProductID that
is
> a key reference.   The xs:key selector might be "catalog/Product".
>
> Now if I add elements (let's say "Shirt" and "Shoes") that have "Product"
as
> a substitution group (they are derived from and can be substituted for
> product) would <Shirt ProductID=34> be considered a keyref (and validated
> accordingly), or would I have to provide a selector that specifically
> matches "Shirt" and "Shoes"?
>
> A second question is... in general... are XML processors that read-in
Schema
> generally "aware" of substitution groups?  That is, in general, do I have
to
> modify XML apps everytime a new element tag is added to the Product
> substitution group?
>
> Thanks
>
>