<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE document SYSTEM "section.dtd">
<document>
	<section id="sgml" author="dret">
		<title>Standard Generalized Markup Language (SGML)</title>
		<p>SGML is an ISO standard ...</p>
		<section id="sgml-syntax" author="bob">
			<title>SGML Syntax</title>
			<p>SGML uses markup, which is ...</p>
		</section>
	</section>
	<section id="xml" author="bob">
		<title>Extensible Markup Language (XML)</title>
		<p>XML is based on SGML (Section <ref name="sgml"/>) ...</p>
		<p type="example">XML can be used ...</p>
		<section id="xml-syntax" author="dret">
			<title>XML Syntax</title>
			<p>Section <ref name="sgml-syntax"/> describes ...</p>
		</section>
	</section>
</document>
