"http://www.w3.org/Graphics/SVG/svg-19990412.dtd">

<svg width="4in" height="3in">

  <desc>Example of using a mask

  </desc>

  <g>

    <defs>

      <image id="MyMask" href="transp.png"></image>

    </defs>

    <rect style="mask: url(#MyMask)" width="12.5" height="30" />

  </g>

</svg>