Here: http://www.w3.org/TR/2002/REC-xhtml1-20020801/#media
There is a link in 'For further information on using media types with XHTML, see the informative note [XHTMLMIME].'
It wrongly points to [RFC3066], but I think it should point to [RFC3236], as correctly.
-- Me at: http://WalkinRaven.name
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