In addition to tags, elements, and attributes, you can insert the following declarations in an XML document:
Prolog
Comments
Empty elements
The CDATA section
Processing instructions
<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?> <!-- This is the first message in the document -->
<message> <priority type="urgent"/>
<to>you@yourAddress.com</to>
<from>me@myAddress.com</from>
<code> <![CDATA[<tag> content </tag>]]>
<code>
<subject >Car lights on</subject> <?cocoon-process type="xslt"?>
<body type=" text without graphic">
Owner of vehicle with license plate
454-561, your lights are on!
</body>
</message>