Created attachment 1317 [details]
Screenshot of meaningless warning.

Steps to repeat:

1. Locate a page of the following characteristics:
   a. has XHTML5 markup.
   b. has <meta charset="UTF-8"/>
   c. has Content-Type text/html *without* charset parameter
   d. is served via HTTP or via data URI
2. Check the page with XML parser: http://tinyurl.com/a95tvf8

Expected result: Since the page contains <meta charset="UTF-8"/>
                 the page uses UTF-8 encoding in the text/html 
                 Content-Type and will therefore not cause any 
                 error message despite that the Content-Type
                 lacks the charset parameter: 
                 http://tinyurl.com/aeuwqz9

                 Therefore I wouldn't expect that overriding the
                 Content-Type ("lax about Content-Type") would 
                 cause any warning with regard to the charset
                 paramter of the *original* Content-Type.

  Actual result: Validator gives a confusing message were it
                 claims that it, quote, "Would have defaulted to 
                 US-ASCII had the lax option not been chosen."