While looking for something completely different I stumbled across this article by Jeffrey Zeldman. It explains in detail some issues related to the DOCTYPE which I’ve never thought of.

You’ve done all the right stuff, but your site doesn’t look or work as it should in the latest browsers.

You’ve written valid XHTML and CSS. You’ve used the W3C standard Document Object Model (DOM) to manipulate dynamic page elements. Yet, in browsers designed to support these very standards, your site is failing. A faulty DOCTYPE is likely to blame.

This little article will provide you with DOCTYPEs that work, and explain the practical, real–world effect of these seemingly abstract tags.

What I really was after is explained in detail at Pat’s Place in the article about how to Attach icons to anything with CSS. I’ll post a follow-up on that subject later as I’ve just implemented the technique described on this site.

I will during the weekend spend some time looking into the DOCTYPE issue, and maybe get some answers to why IE does strange things when you least expect it.