Ejemplo de una DTD para codificar nombres de persona
<!ELEMENT person (name, profession*)>
<!ELEMENT name (first_name, last_name)>
<!ELEMENT first_name (#PCDATA)>
<!ELEMENT last_name (#PCDATA)>
<!ELEMENT profession (#PCDATA)>
<!ELEMENT person (name, profession*)>
<!ELEMENT name (first_name, last_name)>
<!ELEMENT first_name (#PCDATA)>
<!ELEMENT last_name (#PCDATA)>
<!ELEMENT profession (#PCDATA)>