On Mon, Apr 12, 2010 at 9:13 PM, Aryeh Gregor <Simetrical+wikilist@gmail.comSimetrical%2Bwikilist@gmail.com
wrote:
W3C validation isn't relevant here. Sites get blacklisted by Microsoft if they don't work well in IE8, for any reason. Invalid markup isn't a major issue for us, but we might be triggering IE8 bugs or misfeatures for other reasons.
Might well be one of enWPs templates or infoboxes triggered it... but without a transparent documentation by Microsoft we will never know for sure.
Marco
PS: That wikipedia.de has invalid HTML in contrast to all wikis, which are all valid HTML (except the CSS), is easy to explain: wikipedia.de is not run with mediawiki under the hood, and mediawiki employs Tidy to output correct HTML. Which is bad, because it doesn't force template / infobox devs to write proper code which can be re-used in other wikis!