<simpleType name="VaneEnumType">
  <restriction base="string">
    <enumeration value="double tapered">
      <annotation>
        <documentation>A vane tapered at both ends.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="rectangular">
      <annotation>
        <documentation>A rectangular vane, with no taper.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="single tapered">
      <annotation>
        <documentation>A vane tapered at one end.</documentation>
      </annotation>
    </enumeration>
  </restriction>
</simpleType>