<xs:attribute name="class">
    <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
            <xs:enumeration value="box" />
            <xs:enumeration value="deck" />
            <xs:enumeration value="byline" />
            <xs:enumeration value="dateline" />
            <xs:enumeration value="sidebar" />
            <xs:enumeration value="lead-in" />
            <xs:enumeration value="fnRef" />
            <xs:enumeration value="fnBody" />
            <xs:enumeration value="fnKey" />
            <xs:enumeration value="pullQuote" />
            <xs:enumeration value="teaser" />
        </xs:restriction>
    </xs:simpleType>
</xs:attribute>