P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="num">
<rng:ref name="att.global.attributes"/>
<rng:optional>
 <rng:attribute name="type">
  <rng:choice>
   <rng:value>cardinal</rng:value>
   <rng:value>ordinal</rng:value>
   <rng:value>fraction</rng:value>
   <rng:value>percentage</rng:value>
   <rng:data type="Name"/>
  </rng:choice>
 </rng:attribute>
</rng:optional>
<rng:optional>
 <rng:attribute name="value">
  <rng:ref name="data.numeric"/>
 </rng:attribute>
</rng:optional>
<rng:ref name="macro.phraseSeq"/>
</rng:element>

element num
{
   att.global.attributes,
   attribute type
   {
      "cardinal" | "ordinal" | "fraction" | "percentage" | xsd:Name
   }?,
   attribute value { data.numeric }?,
   macro.phraseSeq
}