Problems with the namespace of substitution groups

I'm having trouble making substitution groups work. In the specification the
example given of a substitution group has

<xs:element name="facet" type="xs:facet" abstract="true"/>

 <xs:element name="encoding" substitutionGroup="xs:facet">

where facet has been defined using <xs:complexType name="facet">

I'm trying to work out what the significance of the addition of the xs:
namespace to the type definition for the abstract element and for the
substitutionGroup attribute.  Could this be something to do with the reason
that if I try to import a file containing just the complexType and abstract
element definitions into a schema that is designed to instatiate the
abstract instances I start getting error messages from XML Spy? What is the
relationship of the name space of an abstract element or complexType
definition to the targetNamespace and the null namespace (xmlns=...)
properties of the containing schemas?

Martin Bryan
Technical Manager, The Diffuse Project

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Received on Friday, 26 January 2001 06:58:33 UTC