<xs:attribute name="SearchType" use="optional">
    <xs:annotation>
        <xs:documentation xml:lang="en">Specifies (at a high level) the type of search criteria for
this request.</xs:documentation>
    </xs:annotation>
    <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
            <xs:enumeration value="Normal">
                <xs:annotation>
                    <xs:documentation xml:lang="en">No special conditions (default)</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="Window">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Search should be done for a window of time.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="ArrivalTime">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Search should be based on arrival time.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="PowerFlight">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Checks availability and fares by manually entered data.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="AvailableOnly">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Check for available flights.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="WaitlistOnly">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Only check only for waitlist flights.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="AvailableAndWaitlist">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Check for available and waitlisted flights.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
            <xs:enumeration value="FreighterFlights">
                <xs:annotation>
                    <xs:documentation xml:lang="en">Check for available freighter flights.</xs:documentation>
                </xs:annotation>
            </xs:enumeration>
        </xs:restriction>
    </xs:simpleType>
</xs:attribute>