[BCP116]   Best Current Practice 116,
              <https://www.rfc-editor.org/info/bcp116>.
              At the time of writing, this BCP comprises the following:

              Martini, L., "IANA Allocations for Pseudowire Edge to Edge
              Emulation (PWE3)", BCP 116, RFC 4446,
              DOI 10.17487/RFC4446, April 2006,
              <https://www.rfc-editor.org/info/rfc4446>.