In my opinion, from HTML5, and not XHTML5, there should also exist a leading prolog like
<?html version="5.0" encoding="utf-8"> For XHTML5, we will continue using the XML prolog ; but it *may* be followed by the html prolog, without needing to repeat the optional encoding pseudo-attribute, which XML parsers will treat as a parsing instruction: <?xml version="1.0" encoding="utf-8"> <?html version="5.0"> The absence of these prologs, will use the default encoding of each parser. Autosensing of document types wil remain possible and HTML5 will also no longer be dependant of transport protocols or to the very ugly <meta http-equiv="Content-type" value="text/html;charset=utf-8"> element which forces the reparsing. The pseudo DOCTYPE tentatively introduced in HTML5 which breaks in SGML parsers and in past HTML parsers, should be eliminated from HTML5 if the HTML prolog is present (the HTML prolog would be highly prefered, including with its useful versioning).
