<!DOCTYPE html>
<base href="http://www.example.com/">
<svg>
  <pattern id="pattern" width="100" height="100" patternUnits="userSpaceOnUse">
    <rect width="100" height="100" fill="green"/>
  </pattern>
  <pattern id="inheritedPattern" href="#pattern"/>
  <rect width="100" height="100" fill="url(#inheritedPattern) red"/>
</svg>