[STD98]    Internet Standard 98,
              <https://www.rfc-editor.org/info/std98>.
              At the time of writing, this STD comprises the following:

              Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
              Ed., "HTTP Caching", STD 98, RFC 9111,
              DOI 10.17487/RFC9111, June 2022,
              <https://www.rfc-editor.org/info/rfc9111>.