Language Resource Management -- Morpho-syntactic Annotation Framework (MAF)

<rng:element name="token">
<rng:ref name="att.maf.globals"/>
<rng:ref name="att.token.information"/>
<rng:choice>
 <rng:ref name="att.token.span"/>
 <rng:group>
  <rng:ref name="att.token.join"/>
  <rng:text/>
 </rng:group>
</rng:choice>
</rng:element>

element token
{
   att.maf.globals,
   att.token.information,
   ( att.token.span | ( att.token.join, text ) )
}