Noscope

Showing CSS to IE only (The Underscore Hack)

January 23rd, 2005 bugs, css, ie

Recently, I stumbled upon (via Mr. van Kesteren) the best CSS “hack” you’ll ever use in CSS sites.

It allows you to show CSS to Internet Explorer only, omitting Mozilla, Safari and Opera.

This is different from conditional comments in the following way:

• It allows you to write conditional CSS directly in your stylesheet file, and doesn’t require inline styles
• It works for IE 5.0, 5.5 and 6.0
• It’s a hack
• It’s very simple to work with.

The hack is called the “Underscore Hack”, and apparently it’s been around for a while. For the benefit of those of us who didn’t know about it, I’m posting it here:

body {
    background: green; /* show to Mozilla/Safari/Opera */
    _background: red; /* show to IE */
}

Cons

• The CSS won’t validate
• The hack won’t work for IE5/Mac. For this platform, I recommend the IE5/Mac Band Pass Filter hack

Sample Page

• View sample page, including CSS

More Information on CSS filtering

John Serris has done an indepth write-up on various other methods of filtering CSS. It is definitely worth a visit:

• Managing CSS Hacks

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