Cutting the Mustard: Preventing CSS Delivery in IE and Old Browsers

<link id="mustardcut" rel="stylesheet" href="stylesheet.css" media="
    only screen,
    only all and (pointer: fine), only all and (pointer: coarse), only all and (pointer: none),
    min--moz-device-pixel-ratio:0) and (display-mode:browser), (min--moz-device-pixel-ratio:0)
"
>

Source