<xs:attributeGroup name="CodeListGroup">
    <xs:annotation>
        <xs:documentation xml:lang="en">Used to specify a code and its associated attributes; meaning is derived from actual use.</xs:documentation>
    </xs:annotation>
    <xs:attributeGroup ref="CodeGroup">
        <xs:annotation>
            <xs:documentation xml:lang="en">Used to specify a code and the context of the code.</xs:documentation>
        </xs:annotation>
    </xs:attributeGroup>
    <xs:attribute name="URI" type="xs:anyURI" use="optional">
        <xs:annotation>
            <xs:documentation xml:lang="en">Identifies the location of the code table</xs:documentation>
        </xs:annotation>
    </xs:attribute>
    <xs:attributeGroup ref="QuantityGroup">
        <xs:annotation>
            <xs:documentation xml:lang="en">Specifies the number of items that are identified by the Code (e.g., 2 adults, 5 first class seats).</xs:documentation>
        </xs:annotation>
    </xs:attributeGroup>
</xs:attributeGroup>