P5: Linee guida per la codifica e l'interscambio del testo elettronico

<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? ) )
}