"match" href="../reference/no-red-on-blank-page-ref.xht"/>
        <meta name="flags" content="ahem" />
        <meta name="assert" content="The 'clip' property sets a zero value, in 'em' units, for all sides of the clipping rectangle." />
        <link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
        <style type="text/css">
            div
            {
                background: red;
                clip: rect(0em, 0em, 0em, 0em);
                font: 20px/1 Ahem;
                heigh