familie.xml

<?xml version="1.0"?>
<!-- Tip atribut: ID, IDREF -->
<!-- Valoare implicita: #REQUIRED, #IMPLIED -->
<!DOCTYPE familie [
<!ELEMENT familie (persoana*)>
<!ELEMENT persoana (#PCDATA)>
<!ATTLIST persoana id ID #REQUIRED>
<!ATTLIST persoana tata IDREF #IMPLIED>
<!ATTLIST persoana mama IDREF #IMPLIED>
<!ATTLIST persoana parinti IDREFS #IMPLIED>
]>
<familie>
    <persoana id="p1">Vasile</persoana>
    <persoana id="p2">Ana</persoana>
    <persoana id="p3" tata="p1" mama="p2">Ioana</persoana>
    <persoana id="p4" parinti="p1 p2">Cristian</persoana>
</familie>