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

<rng:element name="additional">
<rng:ref name="att.global.attributes"/>
<rng:group>
 <rng:optional>
  <rng:ref name="adminInfo"/>
 </rng:optional>
 <rng:optional>
  <rng:ref name="surrogates"/>
 </rng:optional>
 <rng:optional>
  <rng:ref name="listBibl"/>
 </rng:optional>
</rng:group>
</rng:element>

element additional
{
   att.global.attributes,
   ( adminInfo?, surrogates?, listBibl? )
}