Valid XML Documents

• Association with a Document Type Definition (DTD)
• Comply with that DTD

     <?xml version="1.0" encoding="UTF-8"?> 
     <?xml-stylesheet type="text/css" href="first.css"?>
     <!DOCTYPE DOCUMENT [                  
        <!ELEMENT DOCUMENT (GREETING, MESSAGE)>                  
        <!ELEMENT GREETING (#PCDATA)>
        <!ELEMENT MESSAGE (#PCDATA)>
     ]>

     <DOCUMENT>
        <GREETING>Hello from XML</GREETING>
        <MESSAGE>Welcome to Programing XML in Java</MESSAGE>
     </DOCUMENT>