<!– 3.2.3 : 3.1
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="foo"> <complexType> <attribute name="bar" ref="foo:bar" /> </complexType> </element> <attribute name="bar" type="string" />
</schema>