<grammar xmlns:html="http://www.w3.org/TR/REC-html40" xmlns="http://relaxng.org/ns/structure/1.0" >
     <start>
          <element name="foo">
               <zeroOrMore>
                    <attribute>
                         <anyName>
                              <except>
                                   <anyName/>
                              </except>
                         </anyName>
                         <text/>
                    </attribute>
                    <notAllowed/>
               </zeroOrMore>
          </element>
     </start>
</grammar>