A processing instruction that is encountered outside the document type declaration is represented by a syntax element with field type XML.ProcessingInstruction.
This is a name-value element; the name of the syntax element is the processing instruction target name, and the value of the syntax element is the character data of the processing instruction. The value of the syntax element must not be empty. The name cannot be XML in either uppercase or lowercase.
< > & " '
The following shows an example of the XML processing instruction in an XML document:
<example><?target This is a PI.?></example>