P5: Guidelines for Electronic Text Encoding and Interchange

<rng:element name="opener">
<rng:ref name="att.global.attributes"/>
<rng:zeroOrMore>
 <rng:choice>
  <rng:text/>
  <rng:ref name="model.gLike"/>
  <rng:ref name="model.phrase"/>
<!-- shd be class ref -->
  <rng:ref name="argument"/>
  <rng:ref name="byline"/>
  <rng:ref name="dateline"/>
  <rng:ref name="epigraph"/>
  <rng:ref name="salute"/>
  <rng:ref name="signed"/>
  <rng:ref name="model.global"/>
 </rng:choice>
</rng:zeroOrMore>
</rng:element>

element opener
{
   att.global.attributes,
   (
      text
    | model.gLike
    | model.phrase
    | argument
    | byline
    | dateline
    | epigraph
    | salute
    | signed
    | model.global
   )*
}