[STD86]    Internet Standard 86,
              <https://www.rfc-editor.org/info/std86>.
              At the time of writing, this STD comprises the following:

              Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.