[BCP239]   Best Current Practice 239,
              <https://www.rfc-editor.org/info/bcp239>.
              At the time of writing, this BCP comprises the following:

              Kühlewind, M., Reed, J., and R. Salz, "Open Participation
              Principle regarding Remote Registration Fee", BCP 239,
              RFC 9501, DOI 10.17487/RFC9501, December 2023,
              <https://www.rfc-editor.org/info/rfc9501>.