P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="pRef">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.ptrLike.form.attributes"/>
 <rng:ref name="att.lexicographic.attributes"/>
 <rng:empty/>
</rng:element>

element pRef
{
   att.global.attributes,
   att.ptrLike.form.attributes,
   att.lexicographic.attributes,
   empty
}