P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="category">
 <rng:ref name="att.global.attributes"/>
 <rng:group>
  <rng:choice>
   <rng:ref name="catDesc"/>
   <rng:zeroOrMore>
    <rng:ref name="model.glossLike"/>
   </rng:zeroOrMore>
  </rng:choice>
  <rng:zeroOrMore>
   <rng:ref name="category"/>
  </rng:zeroOrMore>
 </rng:group>
</rng:element>

element category
{
   att.global.attributes,
   ( ( catDesc | model.glossLike* ), category* )
}