<!DOCTYPE html>
<base href="http://www.example.com/">
<svg>
  <clipPath id="clip">
    <rect y="50" width="100" height="50"/>
  </clipPath>
  <rect width="100" height="50" fill="green"/>
  <g clip-path="url(#clip)">
    <rect width="100" height="50" fill="red"/>
    <rect y="50" width="100" height="50" fill="green"/>
  </g>
</svg>