<!DOCTYPE html>
<meta charset="utf-8">
<title>href - pattern element reference</title>
<body>
  <svg width="300" height="300" viewBox="0 0 300 300"
       xmlns:xlink="http://www.w3.org/1999/xlink">
    <pattern id="Pattern" x="0" y="0" width=".25" height=".25">
      <rect x="0" y="0" width="25" height="25" fill="skyblue"/>
      <circle cx="25" cy="25" r="20" fill="green" fill-opacity="0.5"/>
    </pattern>
    <rect fill="url(#Pattern)" stroke="black" x="0" y="0"
          width="200" height="200"/>
  </svg>
</body>