There seems to be a mild trend toward adding attributes into the html and head start tags (for example, the Open Graph protocol alone may require at least three). However, the charset must be completely declared within the first 1,024 characters of the file. As of yet, I don't think that's a conflict, but if anyone else wants to require more to be written into those 1024 bytes then we could have a problem. Possibly two solutions exist: get rid of the 1024-byte limit (I suppose there's a reason for it and that should be checked) or limit what can be required within that byte count. The most vulnerable are, I think, the html and head opening tags with new attributes and the doctype declaration if we again require a long one (it's shorter now than it was for HTML4). For example, I think putting the dir, lang, and translate attributes into the html element is either required or recommended when I'm not clear why putting all three into the opening body tag wouldn't suffice for all purposes, since the head element's content is, as far as I know, always left-to-right, in English, and not translated and therefore those attributes are irrelevant for the head element's content. I've already proposed to the Open Graph developers (https://groups.google.com/forum/#!topic/open-graph-protocol/e-ryeBShGY4) an alternative solution to requiring that their several attributes be added to the head opening tag (they can accept declarations being in link or meta tags preceding other tags using OGP), although the size of the installed base may make deprecation difficult or at least very slow.