What happens if I repeat a CSS style in IE?

Question

In jquery-ui-1.8.6.custom.css, I found this gem:

/* IE6 IFRAME FIX (taken from datepicker 1.5.3 */
.ui-datepicker-cover {
    display: none; /*sorry for IE5*/
    display/**/: block; /*sorry for IE5*/
    position: absolute; /*must have*/
    ...
}

Apparently, repeating the display style is a workaround for a bug in IE. If I understand CSS correctly, this should behave like display: block; (i.e. the first entry should be overridden by the second).

For which version(s) of IE is this necessary? Only 5.x or 6 as well?

Answer 1

See: http://www.communis.co.uk/dithered/css_filters/css_only/property_empty_comment.html:

#testElement {
   color/**/: #00cc00;
   }

Applied By
..
Win IE 5.5 - 6.x
..

Not Applied By
Win IE 4.0 - 5.0
..

So, the comment /*sorry for IE5*/ aptly describes the hack - the zero IE5.0 users still in existence will not be able to see any .ui-datepicker-cover elements.