purposeValues

<xs:simpleType name="purposeValues">
  <xs:restriction base="xs:token">
    <xs:enumeration value="discipline"/>
    <xs:enumeration value="idea"/>
    <xs:enumeration value="prerequisite"/>
    <xs:enumeration value="educational objective"/>
    <xs:enumeration value="accessibility restrictions"/>
    <xs:enumeration value="educational level"/>
    <xs:enumeration value="skill level"/>
    <xs:enumeration value="security level"/>
    <xs:enumeration value="competency"/>
  </xs:restriction>
</xs:simpleType>