<xs:attribute name="ResBookDesigCodeType" use="optional">
    <xs:annotation>
        <xs:documentation xml:lang="en">To specify the types of RBD's (Res Book Desig Codes) that should be returned as opposed to a specific RBD.</xs:documentation>
    </xs:annotation>
    <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
            <xs:enumeration value="Displayable">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Only return displayable RBDs.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="NonDisplayable">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Only return non-displayable RBD's.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="All">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Return all RBD's, displayable and non-displayable.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
        </xs:restriction>
    </xs:simpleType>
</xs:attribute>