<simpleType name="CodeNavigationSpecificationBaseType">
    <union>
        <simpleType>
            <restriction base="string">
                <enumeration value="RNAV_10" />
                <enumeration value="RNAV_5" />
                <enumeration value="RNAV_2" />
                <enumeration value="RNAV_1" />
                <enumeration value="RNP_4" />
                <enumeration value="RNP_2" />
                <enumeration value="BASIC_RNP_1" />
                <enumeration value="ADVANCED_RNP_1" />
                <enumeration value="RNP_APCH" />
                <enumeration value="RNP_AR_APCH" />
            </restriction>
        </simpleType>
        <simpleType>
            <restriction base="string">
                <pattern value="OTHER(:(\w|_){1,58})?" />
            </restriction>
        </simpleType>
    </union>
</simpleType>

• CodeNavigationSpecificationBaseType
• aixm:CodeNavigationSpecificationType
• aixm:navigationSpecification