Well, you still can write XML compliant modern HTML. Just don't forget to serve it with HTTP header: `Content-Type: application/xhtml+xml; charset=utf-8`. The

Well, you still can write XML compliant modern HTML. Just don't forget to serve it with HTTP header: `Content-Type: application/xhtml+xml; charset=utf-8`. The browser will treat it as XML. But that is not true for all HTML, of course. So you are kind of right.