[BCP227]   Best Current Practice 227,
              <https://www.rfc-editor.org/info/bcp227>.
              At the time of writing, this BCP comprises the following:

              Velvindron, L., "Deprecating RC4 in Secure Shell (SSH)",
              BCP 227, RFC 8758, DOI 10.17487/RFC8758, April 2020,
              <https://www.rfc-editor.org/info/rfc8758>.