Exemple d'utilisation de namespaces multiples (W3C)

<?xml version="1.0"?>
<!-- initially, the default namespace is "books" -->
<book xmlns='urn:loc.gov:books'
      xmlns:isbn='urn:ISBN:0-395-36341-6'>
  <title>Cheaper by the Dozen</title>
  <isbn:number>1568491379</isbn:number>
  <notes>
  <!-- make HTML the default namespace for some commentary -->
    <p xmlns='urn:w3-org-ns:HTML'>
     This is a <i>funny</i> book!
    </p>
  </notes>
</book>