<xs:element name="documentation" maxOccurs="unbounded">
    <xs:complexType>
        <xs:simpleContent>
            <xs:extension base="xs:string">
                <xs:attribute name="type" use="required">
                    <xs:simpleType>
                        <xs:restriction base="xs:NMTOKEN">
                            <xs:enumeration value="description" />
                            <xs:enumeration value="note" />
                            <xs:enumeration value="license" />
                            <xs:enumeration value="usage" />
                            <xs:enumeration value="other" />
                        </xs:restriction>
                    </xs:simpleType>
                </xs:attribute>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>
</xs:element>