<!– 3.2.3 : 2.1
One of ref or name must be present, but not both.
–> <schema xmlns=“www.w3.org/2001/XMLSchema” targetNamespace=“foo” xmlns:foo=“foo”>
<element name="bar" type="string"/> <element name="foo"> <complexType> <sequence> <element name="bar" ref="foo:bar"/> </sequence> </complexType> </element>
</schema>