<xs:element name="Standard">
    <xs:simpleType>
        <xs:restriction base="xs:token">
            <xs:enumeration value="ASTM D2369" />
            <xs:enumeration value="ASTM E1333" />
            <xs:enumeration value="CEN/TS 16516:2013" />
            <xs:enumeration value="CEN/TS 16516:2017" />
            <xs:enumeration value="CDPH Standard Method v1.1" />
            <xs:enumeration value="EN 717-1" />
            <xs:enumeration value="EN 717-1:2004" />
            <xs:enumeration value="EN 717-1:2006" />
            <xs:enumeration value="EN 717-2" />
            <xs:enumeration value="EN 717-3" />
            <xs:enumeration value="EN 120" />
            <xs:enumeration value="EN 120:1992" />
            <xs:enumeration value="EN 13999" />
            <xs:enumeration value="EN 16402:2013" />
            <xs:enumeration value="EN 16516" />
            <xs:enumeration value="EN 16516:2017/FprA1" />
            <xs:enumeration value="EN 16516:2018" />
            <xs:enumeration value="EN 16516:2018-01" />
            <xs:enumeration value="EN ISO 12460-3" />
            <xs:enumeration value="ISO/DIS 12460-4" />
            <xs:enumeration value="EN ISO 12460-5" />
            <xs:enumeration value="ISO 10580:2010" />
            <xs:enumeration value="ISO 11890-1" />
            <xs:enumeration value="ISO 11890-1:2007" />
            <xs:enumeration value="ISO 11890-1:2024" />
            <xs:enumeration value="ISO 11890-2" />
            <xs:enumeration value="ISO 11890-2:2013" />
            <xs:enumeration value="ISO 11890-2:2020" />
            <xs:enumeration value="ISO 17895:2005" />
            <xs:enumeration value="ISO 16000-3:2011" />
            <xs:enumeration value="ISO 16000-3:2013-01" />
            <xs:enumeration value="ISO 16000-9:2006" />
            <xs:enumeration value="ISO 16000-10:2006" />
            <xs:enumeration value="ISO 16000-28:2012" />
            <xs:enumeration value="JAS 233" />
            <xs:enumeration value="JIS A 1460" />
            <xs:enumeration value="NIOSH 6015:1994" />
            <xs:enumeration value="RISE method 2302" />
            <xs:enumeration value="RISE method 1598" />
            <xs:enumeration value="EC 1907/2006 Annex XVII" />
        </xs:restriction>
    </xs:simpleType>
</xs:element>