test/SVG/viewport-nest.xml

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG April 1999//EN" 
  "http://www.w3.org/Graphics/SVG/svg-19990412.dtd">
<svg width="4in" height="3in">
  <desc>This SVG drawing embeds another one,
    thus establishing a new viewport
  </desc>
  <!-- The following statement establishing a new viewport
       and renders SVG drawing B into that viewport -->
  <svg style="left: 25%; top: 25%" width="50%" height="50%">
     <!-- drawing B goes here -->
  </svg>
</svg>