[BCP191]   Best Current Practice 191,
              <https://www.rfc-editor.org/info/bcp191>.
              At the time of writing, this BCP comprises the following:

              Eastlake 3rd, D., "IANA Considerations for Connectivity
              Fault Management (CFM) Code Points", BCP 191, RFC 7319,
              DOI 10.17487/RFC7319, July 2014,
              <https://www.rfc-editor.org/info/rfc7319>.