<book title="Manual" cover="gbook:covers/default" fontSize="0.4">
  <chapter>
    <section>
      <page_title>
        <title>Index</title>
      </page_title>
      <link ref="Island">1. Island</link>
    </section>
  </chapter>
  <chapter id="Island">
    <section>
      <page_title>
        <title>Island</title>
      </page_title>
      <p>You can create your island with the command /island create</p>
    </section>
  </chapter>
</book>