<simpleType name="CodeRouteDesignatorLetterBaseType">
    <union>
        <simpleType>
            <restriction base="string">
                <enumeration value="A" />
                <enumeration value="B" />
                <enumeration value="G" />
                <enumeration value="H" />
                <enumeration value="J" />
                <enumeration value="L" />
                <enumeration value="M" />
                <enumeration value="N" />
                <enumeration value="P" />
                <enumeration value="Q" />
                <enumeration value="R" />
                <enumeration value="T" />
                <enumeration value="V" />
                <enumeration value="W" />
                <enumeration value="Y" />
                <enumeration value="Z" />
            </restriction>
        </simpleType>
        <simpleType>
            <restriction base="string">
                <pattern value="OTHER(:(\w|_){1,58})?" />
            </restriction>
        </simpleType>
    </union>
</simpleType>

• CodeRouteDesignatorLetterBaseType
• aixm:CodeRouteDesignatorLetterType
• aixm:designatorSecondLetter