|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
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.