type

<xs:attribute name="type" use="required">
  <xs:simpleType>
    <xs:restriction base="xs:NMTOKEN">
      <xs:enumeration value="credit"/>
      <xs:enumeration value="payment"/>
      <xs:enumeration value="licensing"/>
      <xs:enumeration value="reporting"/>
    </xs:restriction>
  </xs:simpleType>
</xs:attribute>