[BCP202]   Best Current Practice 202,
              <https://www.rfc-editor.org/info/bcp202>.
              At the time of writing, this BCP comprises the following:

              Yourtchenko, A. and L. Colitti, "Reducing Energy
              Consumption of Router Advertisements", BCP 202, RFC 7772,
              DOI 10.17487/RFC7772, February 2016,
              <https://www.rfc-editor.org/info/rfc7772>.