All legal text characters that can appear anywhere in an XML document can appear in #PCDATA. This includes characters like < and & that may have to be escaped with character or entity references. When an API presents the content of a node containing such a character to your code, it will give you the actual character, not the escaping text. Similarly, when you create such a node, the string you use should contain the actual character, not the entity or character reference.
Consider the following DocBook programlisting element. A CDATA section is used to embed a literal sequence of XML text.
<programlisting><![CDATA[<value> <double>28657</double> </value>]]></programlisting>
Everything inside the CDATA section ...