Spaze asked about epub xhtml support. Why would you look in CSS? Look in ePUB for the xhtml support. Now the CSS_HowTo does need some work but that has nothing to do with this thread which asked about xhtml. Having said that you are welcome to improve the information in
CSS HowTo. A good source would be the thread in the ePUB section with CSS examples, plus your own knowledge. Our wiki is a group effort. Join in!
Dale