what is the difference between width/margin and _width/_margin?

css

Solution

It is a hack for IE6. The CSS rules `_margin` and `_width` will only apply for that browser. There are more curious hacks for the IE browser like:

width: 940px\9; /* IE8 and below */  
*width : 960px; /* IE7 and below */

If you make a fast search in google for "IE CSS hacks" you can find more information and tricks for CSS rules in the evil IE like: Quick Tip: How to Target IE6, IE7, and IE8 Uniquely with 4 Characters

Problem

``` .pageWidth { margin: 0 30px; min-width: 940px; _width: 976px; _margin: 0 auto; } ``` I saw this from a website css file. My question is: what is the difference between width/margin and _width/_margin? why use _width/_margin here?

Original source