XML provides the CDATA markup to allow a region of text in which most of the XML delimiter recognition does not take place. This is intended to ease the task of quoting XML fragments and other programmatic information in a document's text without needing to escape these special characters. It's primarily a convenience feature for those who are hand-editing XML.

CDATASection is an Extended DOM feature, and is not used in HTML contexts.

Within the DOM, CDATASections are treated essentially as Text blocks. Their distinct type is retained in order to allow us to properly recreate the XML syntax when we write them out.

Reminder: CDATA IS NOT A COMPLETELY GENERAL SOLUTION; it can't quote its own end-of-block marking. If you need to write out a CDATA that contains the ]]> sequence, it's your responsibility to split that string over two successive CDATAs at that time.

CDATA does not participate in Element.normalize() processing.