<simpleType name="CodeApproachGuidanceBaseType">
    <union>
        <simpleType>
            <restriction base="string">
                <enumeration value="NON_PRECISION" />
                <enumeration value="ILS_PRECISION_CAT_I" />
                <enumeration value="ILS_PRECISION_CAT_II" />
                <enumeration value="ILS_PRECISION_CAT_IIIA" />
                <enumeration value="ILS_PRECISION_CAT_IIIB" />
                <enumeration value="ILS_PRECISION_CAT_IIIC" />
                <enumeration value="ILS_PRECISION_CAT_IIID" />
                <enumeration value="MLS_PRECISION" />
            </restriction>
        </simpleType>
        <simpleType>
            <restriction base="string">
                <pattern value="OTHER(:(\w|_){1,58})?" />
            </restriction>
        </simpleType>
    </union>
</simpleType>

• CodeApproachGuidanceBaseType
• aixm:CodeApproachGuidanceType
• aixm:landingSystemCategory
• aixm:precisionApproachGuidance