<?xml version="1.0"?> <!DOCTYPE PARENT [ <!ELEMENT PARENT (CHILD*)> <!ELEMENT CHILD (MARK?,NAME+)> <!ELEMENT MARK EMPTY> <!ELEMENT NAME (LASTNAME+,FIRSTNAME+)*> <!ELEMENT LASTNAME (#PCDATA)> <!ELEMENT FIRSTNAME (#PCDATA)> <!ATTLIST MARK NUMBER ID #REQUIRED LISTED CDATA #FIXED "yes" TYPE (natural|adopted) "natural"> <!ENTITY STATEMENT "This is well-formed XML"> ]> <PARENT> &STATEMENT; <CHILD> <MARK NUMBER="1" LISTED="yes" TYPE="natural"/> <NAME> <LASTNAME>child</LASTNAME> <FIRSTNAME>second</FIRSTNAME> </NAME> </CHILD> </PARENT>