R. Gellens, D. Singer, P. Frojdh. <a href="http://www.ietf.org/rfc/rfc4281.txt"><cite>The Codecs Parameter for &quot;Bucket&quot; Media Types</cite></a> November 2005. Internet RFC 4281. URL: <a href="http://www.ietf.org/rfc/rfc4281.txt">http://www.ietf.org/rfc/rfc4281.txt</a>