<?xml version="1.0" encoding="UTF-8"?>
<doctype>
  <param name="e1">foo|bar</param>
  <modelGroup name="e2">
    <choice>
      <elementRef>
        <name>foo</name>
      </elementRef>
      <zeroOrMore>
        <elementRef>
          <name>bar</name>
        </elementRef>
      </zeroOrMore>
    </choice>
  </modelGroup>
  <element>
    <name>doc</name>
    <modelGroupRef name="e2"/>
  </element>
</doctype>
