status

<xs:attribute name="status" default="unknown">
  <xs:simpleType>
    <xs:restriction base="xs:NMTOKEN">
      <xs:enumeration value="high"/>
      <xs:enumeration value="medium"/>
      <xs:enumeration value="low"/>
      <xs:enumeration value="unknown"/>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>