2.7 CDATA Sections
[Definition: CDATA sections MAY occur anywhere character data may occur; they are used to escape blocks of text containing characters which would otherwise be recognized as markup. CDATA sections begin with the string "<![CDATA[" and end with the string "]]>":]
 CDSect ::= CDStart CData CDEnd
 CDStart ::= '<![CDATA['
 CData ::= (Char* - (Char* ']]>' Char*))
 CDEnd ::= ']]>'
Within a CDATA section, only the CDEnd string is recognized as markup, so that left angle brackets and ampersands may occur in their literal form; they need not (and cannot) be escaped using "<" and "&". CDATA sections cannot nest.
An example of a CDATA section, in which "<greeting>" and "</greeting>" are recognized as character data, not markup: