P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="datatype">
<rng:ref name="att.global.attributes"/>
<rng:optional>
 <rng:attribute name="minOccurs" a:defaultValue="1">
  <rng:ref name="data.count"/>
 </rng:attribute>
</rng:optional>
<rng:optional>
 <rng:attribute name="maxOccurs" a:defaultValue="1">
  <rng:choice>
   <rng:ref name="data.count"/>
   <rng:value>unbounded</rng:value>
  </rng:choice>
 </rng:attribute>
</rng:optional>
<rng:zeroOrMore>
 <rng:group>
  <rng:ref name="macro.schemaPattern"/>
 </rng:group>
</rng:zeroOrMore>
</rng:element>

element datatype
{
   att.global.attributes,
   attribute minOccurs { data.count }?,
   attribute maxOccurs { data.count | "unbounded" }?,
   macro.schemaPattern*
}