1.    [BCP90]    Klyne, G., Nottingham, M., and J. Mogul, "Registration
    2.               Procedures for Message Header Fields", BCP 90, RFC 3864,
    3.               September 2004.
    5.    [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
    6.               Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
    7.               Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
    9.    [RFC4918]  Dusseault, L., Ed., "HTTP Extensions for Web Distributed
    10.               Authoring and Versioning (WebDAV)", RFC 4918, June 2007.