 HTTP/1.1",
              <a href="./rfc2068">RFC 2068</a>, January 1997.

   [<a name="ref-RFC3253" id="ref-RFC3253">RFC3253</a>]  Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J.
              Whitehead, "Versioning Extensions to WebDAV (Web
              Distributed Authoring and Versioning)", <a href="./rfc3253">RFC 3253</a>,
              March 2002.

   [<a name="ref-RFC3648" id="ref-RFC3648">RFC3648</a>]  Whitehead, J. and J. Reschke, Ed., "Web Distributed
              Authoring and Versioning 