Use of conditional comments to target certain versions of Internet Explorer is pretty commonplace nowadays, and is generally seen as the best-practice method for including separate styles for IE.

Of course, I’ve argued in a previous article that if your IE-only styles are minimal, then you should just include them in your main stylesheet, a notion that others have echoed.

But conditional comments have some unique possibilities and quirks that maybe you haven’t considered before, or have simply forgotten. Here is an overview of some things you may not know about conditional comments.