What is the correct MIME type to use for an RSS feed?
Other commenters have pointed out that the single correct mime type is
However, if you are setting an accept header for a client then
Accept: application/rss+xml, application/rdf+xml;q=0.8, application/atom+xml;q=0.6, application/xml;q=0.4, text/xml;q=0.4
might be a good choice, as it states that it accepts RSS, Atom, and XML (in descending order or preference).