<?xml version="1.0"?>
<svg xmlns="http://www.w3.org/2000/svg"
     xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
    <clipPath id="myclip">
        <path d="M 200 200 l 100 0 l 0 200 l -100 0 Z"/>
    </clipPath>
</defs>
<g font-size="55">
<text y="125" fill="green">PASS</text>
<text y="125" fill="red" clip-path="url(#myclip)">FAIL (should be clipped out)</text>
</g>
</svg>