If the example contains material in XML markup, either it must be enclosed within
a CDATA marked section, or character entity references must be used to represent the
markup delimiters. If the example contains well-formed XML, it should be marked using
the more specific egXML element.
Esempio
<p>The <gi>term</gi> element is declared using the following syntax: <eg><![CDATA[<!ELEMENT term (%phrase.content;)>]]</eg> </p>