source: stylesheets/lfs-xsl/docbook-xsl-1.78.1/roundtrip/sections-spec.xml@ c158fe6

<group:root xmlns:group='http://www.explain.com.au/grouping'>
  <book styles='book book-title'>
    <group:level>
      <group:element name='part' styles='part part-title'/>
      <group:element name='article' styles='article article-title'/>
      <group:element name='bibliography' styles='bibliography bibliography-title'/>
      <group:element name='appendix' styles='appendix appendix-title'/>
      <group:element name='chapter' styles='chapter chapter-title'/>
      <group:element name='preface' styles='preface preface-title'/>

      <sect1 styles='sect1 sect1-title'>
        <sect2 styles='sect2 sect2-title'>
          <sect3 styles='sect3 sect3-title'>
            <sect4 styles='sect4 sect4-title'>
              <sect5 styles='sect5 sect5-title'/>
            </sect4>
          </sect3>
        </sect2>
      </sect1>
    </group:level>
  </book>
  <group:level>
    <group:element name='article' styles='article article-title'/>
    <group:element name='appendix' styles='appendix appendix-title'/>
    <group:element name='chapter' styles='chapter chapter-title'/>
    <group:element name='preface' styles='preface preface-title'/>

    <sect1 styles='sect1 sect1-title'>
      <sect2 styles='sect2 sect2-title'>
        <sect3 styles='sect3 sect3-title'>
          <sect4 styles='sect4 sect4-title'>
            <sect5 styles='sect5 sect5-title'/>
          </sect4>
        </sect3>
      </sect2>
    </sect1>
  </group:level>
</group:root>