<xs:complexType name="attribute" abstract="true" >
  <xs:complexContent mixed="false">
    <xs:extension base="xs:annotated">
      <xs:sequence>
        <xs:element minOccurs="0" name="simpleType" type="xs:localSimpleType"/>
      </xs:sequence>
      <xs:attributeGroup ref="xs:defRef"/>
      <xs:attribute name="type" type="xs:QName"/>
      <xs:attribute default="optional" name="use" use="optional">
        <xs:simpleType>
          <xs:restriction base="xs:NMTOKEN">
            <xs:enumeration value="prohibited"/>
            <xs:enumeration value="optional"/>
            <xs:enumeration value="required"/>
          </xs:restriction>
        </xs:simpleType>
      </xs:attribute>
      <xs:attribute name="default" type="xs:string"/>
      <xs:attribute name="fixed" type="xs:string"/>
      <xs:attribute name="form" type="xs:formChoice"/>
    </xs:extension>
  </xs:complexContent>
</xs:complexType>