<xs:element name="Upgrade" minOccurs="0">
    <xs:annotation>
        <xs:documentation source="Description" xml:lang="en">Upgrade instruction information.</xs:documentation>
    </xs:annotation>
    <xs:complexType>
        <xs:sequence>
            <xs:element name="Instruction" type="xs:string" minOccurs="0" maxOccurs="unbounded">
                <xs:annotation>
                    <xs:documentation source="Description" xml:lang="en">Upgrade instruction text.</xs:documentation>
                </xs:annotation>
            </xs:element>
        </xs:sequence>
        <xs:attribute name="UpgradeMethod" use="optional">
            <xs:annotation>
                <xs:documentation source="Description" xml:lang="en">The upgrade method that should be applied to the offer.</xs:documentation>
            </xs:annotation>
            <xs:simpleType>
                <xs:restriction base="xs:string">
                    <xs:enumeration value="S_SpecialServiceRequest" />
                    <xs:enumeration value="A_AutoUpgrade" />
                </xs:restriction>
            </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="UpgradeDesigCode" type="UpperCaseAlphaLength1to2" use="optional">
            <xs:annotation>
                <xs:documentation xml:lang="en">The upgrade booking class.</xs:documentation>
            </xs:annotation>
        </xs:attribute>
    </xs:complexType>
</xs:element>