<!DOCTYPE html>
<svg>
<clipPath id="clip" clip-path="url(#nosuchclip)">
<rect width="100" height="100"/>
</clipPath>
<mask id="mask"></mask>
<rect width="300" height="100" fill="red"/>
<rect width="100" height="100" fill="green" clip-path="url(#nosuchclip)"/>
<rect transform="translate(100 0)" width="100" height="100" fill="green" clip-path="url(#mask)"/>
<rect transform="translate(200 0)" width="100" height="100" fill="green" clip-path="url(#clip)"/>
</svg>