.. _reference.version: :py:attr:`version` ================== The format and version of the feed. Here is the complete list of known feed types and versions that may be returned in :py:attr:`version`: ============ ==================================================================================== ``atom`` Atom (unknown or unrecognized version) ``atom01`` `Atom 0.1 <http://www.intertwingly.net/blog/1506.html>`_ ``atom02`` `Atom 0.2 <http://diveintomark.org/public/2003/08/atom02spec.txt>`_ ``atom03`` `Atom 0.3 <http://www.mnot.net/drafts/draft-nottingham-atom-format-02.html>`_ ``atom10`` `Atom 1.0 <http://www.ietf.org/rfc/rfc4287>`_ ``cdf`` `CDF <http://www.w3.org/TR/NOTE-CDFsubmit.html>`_ ``rss`` :abbr:`RSS (Rich Site Summary)` (unknown or unrecognized version) ``rss090`` `RSS 0.90 <http://www.purplepages.ie/RSS/netscape/rss0.90.html>`_ ``rss091n`` `Netscape RSS 0.91 <http://my.netscape.com/publish/formats/rss-spec-0.91.html>`_ ``rss091u`` `Userland RSS 0.91 <http://backend.userland.com/rss091>`_ ``rss092`` `RSS 0.92 <http://backend.userland.com/rss092>`_ ``rss093`` `RSS 0.93 <http://backend.userland.com/rss093>`_ ``rss094`` :abbr:`RSS (Rich Site Summary)` 0.94 (no accurate specification is known to exist) ``rss10`` `RSS 1.0 <http://purl.org/rss/1.0/>`_ ``rss20`` `RSS 2.0 <http://blogs.law.harvard.edu/tech/rss>`_ ============ ==================================================================================== If the feed type is completely unknown, :py:attr:`version` will be an empty string. .. tip:: This element always exists, although it may be an empty string if the version can not be determined. .. seealso:: `The Myth of RSS compatibility <http://web.archive.org/web/20110726002019/http://diveintomark.org/archives/2004/02/04/incompatible-rss>`_ Mark Pilgrim's excellent analysis of the extraordinary variety of incompatibilities each version of "RSS" introduced.