<xs:attribute name="rotationtype" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:simpleType>
    <xs:restriction base="xs:string">
      <xs:enumeration value="arithmetic" />
      <xs:enumeration value="counterclockwise" />
      <xs:enumeration value="geographic" />
      <xs:enumeration value="" />
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>