[BCP163]   Best Current Practice 163,
              <https://www.rfc-editor.org/info/bcp163>.
              At the time of writing, this BCP comprises the following:

              Andrews, M., "Locally Served DNS Zones", BCP 163,
              RFC 6303, DOI 10.17487/RFC6303, July 2011,
              <https://www.rfc-editor.org/info/rfc6303>.

              Andrews, M., "Adding 100.64.0.0/10 Prefixes to the IPv4
              Locally-Served DNS Zones Registry", BCP 163, RFC 7793,
              DOI 10.17487/RFC7793, May 2016,
              <https://www.rfc-editor.org/info/rfc7793>.