<xs:attributeGroup name="VoucherGroup">
    <xs:annotation>
        <xs:documentation xml:lang="en">A form of payment using a voucher or coupon.</xs:documentation>
    </xs:annotation>
    <xs:attributeGroup ref="EffectiveExpireOptionalDateGroup">
        <xs:annotation>
            <xs:documentation xml:lang="en">The date when a voucher becomes valid for use, if applicable, and the the date when a voucher or series of coupons expires and is no longer valid.</xs:documentation>
        </xs:annotation>
    </xs:attributeGroup>
    <xs:attribute name="SeriesCode" type="StringLength1to32">
        <xs:annotation>
            <xs:documentation xml:lang="en">Identification of a series of coupons or vouchers identified by serial number(s).</xs:documentation>
        </xs:annotation>
    </xs:attribute>
</xs:attributeGroup>