Exemple de DTD

<!ELEMENT MEMO (A, DE, DATE, SUJET?, MESSAGE) >
<!ATTLIST MEMO SECURITE (public|personnel) 'public'
               STATUS (provisoire|final) #REQUIRED>
<!ELEMENT A (#PCDATA)>
<!ELEMENT DE(#PCDATA)>
<!ELEMENT DATE (#PCDATA)>
<!ELEMENT SUJET (#PCDATA)>
<!ELEMENT MESSAGE (P+)>
<!ELEMENT P (#PCDATA|EM)*>
<!ELEMENT EM (#PCDATA)>