CSS or BS?
We show you a CSS property name. You tell us if it’s real or if we made it up. That’s it. It starts easy. It does not stay easy.
Incomplete List of Mistakes in the Design of CSS [CSS Working Group Wiki]
I think I concur with this list. Although I guess it’s worth remembering that, given the size of the CSS spec, this isn’t an overly-long list.
It’s interesting that quite a few of them are about how things are named. It’s almost as if that’s one of the, say, two hardest things in computer science.