P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="supportDesc">
 <rng:ref name="att.global.attributes"/>
 <rng:optional>
  <rng:attribute name="material">
   <rng:ref name="data.enumerated"/>
  </rng:attribute>
 </rng:optional>
 <rng:choice>
  <rng:oneOrMore>
   <rng:ref name="model.pLike"/>
  </rng:oneOrMore>
  <rng:group>
   <rng:optional>
    <rng:ref name="support"/>
   </rng:optional>
   <rng:optional>
    <rng:ref name="extent"/>
   </rng:optional>
   <rng:optional>
    <rng:ref name="foliation"/>
   </rng:optional>
   <rng:optional>
    <rng:ref name="collation"/>
   </rng:optional>
   <rng:optional>
    <rng:ref name="condition"/>
   </rng:optional>
  </rng:group>
 </rng:choice>
</rng:element>

element supportDesc
{
   att.global.attributes,
   attribute material { data.enumerated }?,
   ( model.pLike+ | ( support?, extent?, foliation?, collation?, condition? ) )
}