<grammar xmlns="http://relaxng.org/ns/structure/1.0">
  <start>
   <element>
      <anyName>
        <except>
          <nsName ns="http://bar.com/"/>
          <nsName ns="http://foo.com/"/>
        </except>
      </anyName>
      <empty/>
   </element>
  </start>
</grammar>

