libxml2/test/SVG/viewport.xml

<?xml version="1.0" standalone="yes"?>
<parent xmlns="http://some.url">
   
   <!-- SVG graphic -->
   <svg xmlns='http://www.w3.org/Graphics/SVG/svg-19990412.dtd'
      width="100px" height="200px">
      <path d="M100,100 Q200,400,300,100"/>
      <!-- rest of SVG graphic would go here -->
   </svg>   
   
</parent>