You're wrong. XHTML1 is integrated in the W3C validator and recognized automatically. The document you cite in the XHTML1 specs has just not been updated.
http://validator.w3.org/check?uri=http%3A%2F%2Fwww.xn--elqus623b.net%2FXKCD%2F1137.html&charset=%28detect+automatically%29&doctype=Inline&group=0 Anyway this http://www.xn--elqus623b.net/XKCD/1137.html site is actually using XHTML1.1 (in its strict schema, not a transitional schema) 2012/11/29 Leif Halvard Silli <xn--mlform-...@xn--mlform-iua.no> > Philippe Verdy, Thu, 29 Nov 2012 10:11:13 +0100: > > > So we would be in a case where it's impossible to warranty full > > compatiblity or interoperability between the two concurrent standards > from > > the same standard body, and promissing the best interoperoperability with > > "past" flavors of HTML (those past flavors are still not in the "past" > > given that two of them are definitely not deprecated for now but fully > > recommended, and HTML5 is still with the "draft" status). > > Section 5.1 of XHTML 1.0 says: [1] 'XHTML Documents which follow the > guidelines set forth in Appendix C, "HTML Compatibility Guidelines" may > be labeled with the Internet Media Type "text/html"' > > And Appendix C, point 9 of XHTML 1.0 says: [2] 'the best approach is to > ensure that the web server provides the correct headers. If this is not > possible, a document that wants to set its character encoding > explicitly must include [ snip ] a meta http-equiv statement (e.g., > <meta http-equiv="Content-type" content="text/html; charset=EUC-JP" > />).' > > > For me, it is normal that the Unicorn validator does not integrate HTML5, > > given its draft status. > > The strange thing is that Unicorn doesn't integrate XHTML1. [1][2] > > [1] http://www.w3.org/TR/xhtml1/#media > [2] http://www.w3.org/TR/xhtml1/#C_9 > -- > leif halvard silli