[STD78]    Internet Standard 78,
              <https://www.rfc-editor.org/info/std78>.
              At the time of writing, this STD comprises the following:

              Schoenwaelder, J., "Simple Network Management Protocol
              (SNMP) Context EngineID Discovery", STD 78, RFC 5343,
              DOI 10.17487/RFC5343, September 2008,
              <https://www.rfc-editor.org/info/rfc5343>.

              Harrington, D. and J. Schoenwaelder, "Transport Subsystem
              for the Simple Network Management Protocol (SNMP)",
              STD 78, RFC 5590, DOI 10.17487/RFC5590, June 2009,
              <https://www.rfc-editor.org/info/rfc5590>.

              Harrington, D. and W. Hardaker, "Transport Security Model
              for the Simple Network Management Protocol (SNMP)",
              STD 78, RFC 5591, DOI 10.17487/RFC5591, June 2009,
              <https://www.rfc-editor.org/info/rfc5591>.

              Hardaker, W., "Transport Layer Security (TLS) Transport
              Model for the Simple Network Management Protocol (SNMP)",
              STD 78, RFC 6353, DOI 10.17487/RFC6353, July 2011,
              <https://www.rfc-editor.org/info/rfc6353>.