<xsd:schema targetNamespace="http://www.example.com/common"
	    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
	    elementFormDefault="qualified"
	    attributeFormDefault="unqualified">

  <xsd:attributeGroup name="CommonAttributes">
    <xsd:attribute name="class" type="xsd:NMTOKEN" use="optional"/>
    <xsd:attribute name="id" type="xsd:ID" use="required"/>
  </xsd:attributeGroup>

</xsd:schema>
