text: <!DOCTYPE html>
  <html>
  <head>
  <link id="s" rel="stylesheet" href="data:text/css,@font-face { font-family: 'F'; src: url('file:///404/'); }">
  </head>
  <body onload="document.getElementById('s').sheet.media.appendMedium('x');"></body>
  </html>
  