[BCP142]   Best Current Practice 142,
              <https://www.rfc-editor.org/info/bcp142>.
              At the time of writing, this BCP comprises the following:

              Guha, S., Ed., Biswas, K., Ford, B., Sivakumar, S., and P.
              Srisuresh, "NAT Behavioral Requirements for TCP", BCP 142,
              RFC 5382, DOI 10.17487/RFC5382, October 2008,
              <https://www.rfc-editor.org/info/rfc5382>.