Significant Bugs and Incompatibilities in Internet Explorer

14 October 2009

Following is a brief description of various bugs that occur in IE6 and IE7 that are not described or alluded to above. This list does not include items that lack support in all three browsers.

IE6 Bugs

Doesn't support styling of the <abbr> element
Doesn't support classes and IDs that begin with a hyphen or underscore
<select> elements always appear at the top of the stack, unaffected by z-index values
:hover pseudo-class values are ignored if anchor pseudo-classes are not in the correct order (:link, :visited, :hover)
An !important declaration on a property is overridden by a 2nd declaration of the same property that doesn't use !important
height behaves like min-height
width behaves like min-width
Left and right margins are doubled on floated elements that touch their parents' side edges
Dotted borders appear identical to dashed borders
line-through for text-decoration property appears higher on the text than on other browsers
List items for an ordered list that have a layout will not increment their numbers, leaving all list items preceded by the number "1"
List items don't support all possible values for list-style-type
List items with a specified list-style-image will not display the image if they are floated
Offers only partial support for @font-face
Some selectors will wrongly match comments and the doctype declaration
If an ID selector combined with a class selector is unmatched, the same ID selector combined with different class selectors will also be treated as unmatched

IE7 Bugs

List items for an ordered list that have a layout will not increment their numbers, leaving all list items preceded by the number "1"
List items don't support all possible values for list-style-type
List items with a specified list-style-image will not display the image if they are floated
Offers only partial support for @font-face
Some selectors will wrongly match comments and the doctype declaration
Some IE bugs not mentioned here occur only under particular circumstances, and are not specific to one particular CSS property or value. See the references below for some of those additional issues.