IE Conditional comments ( internet explorer )

Conditional comments only work in IE, and are thus excellently suited to give special instructions meant only for IE. They are supported from IE 5 onwards.

<!--[if IE 6]>
Special instructions for IE 6 here
<![endif]-->

<p class="accent">
<!--[if IE]>
According to the conditional comment this is IE<br />
<![endif]-->
<!--[if IE 6]>
According to the conditional comment this is IE 6<br />
<![endif]-->
<!--[if IE 7]>
According to the conditional comment this is IE 7<br />
<![endif]-->
<!--[if IE 8]>
According to the conditional comment this is IE 8<br />
<![endif]-->
<!--[if IE 9]>
According to the conditional comment this is IE 9<br />
<![endif]-->
<!--[if gte IE 8]>
According to the conditional comment this is IE 8 or higher<br />
<![endif]-->
<!--[if lt IE 9]>
According to the conditional comment this is IE lower than 9<br />
<![endif]-->
<!--[if lte IE 7]>
According to the conditional comment this is IE lower or equal to 7<br />
<![endif]-->
<!--[if gt IE 6]>
According to the conditional comment this is IE greater than 6<br />
<![endif]-->
<!--[if !IE]> -->
According to the conditional comment this is not IE<br />
<!-- <![endif]-->
</p>

Also note the last one. It has a different syntax, and its contents are shown in all browsers that are not IE:

<!--[if !IE]> -->

SOURCE