<xsd:attributeGroup id="attGp.parentSI" name="parentSI">
    <xsd:attribute id="att.parentSI" name="parentSI" type="namespaceRefType">
        <xsd:annotation>
            <xsd:documentation>
                <h:div class="summary" xmlns:h="http://www.w3.org/1999/xhtml">A dictRef-like reference to the id of the parent SI unit.</h:div>
                <h:div class="description" xmlns:h="http://www.w3.org/1999/xhtml">This parent should occur in this or another dictionary 
                and be accessible through the dictRef mechanism. This attribute is forbidden 
                for SI Units themselves. The mechanism holds for base SI units (7) and 
                all compound (derived) units made by combinations of base Units.</h:div>
                <h:div class="example" href="unit3.xml" xmlns:h="http://www.w3.org/1999/xhtml" />
            </xsd:documentation>
        </xsd:annotation>
    </xsd:attribute>
</xsd:attributeGroup>