"1.2 Normative References reads in part:

• • • • • 
          RFC2618 Aboba, B., Zorn, G., ""RADIUS Authentication Client MIB"", RFC2618, June 1999. http://www.ietf.org/rfc/rfc2618.txt.

and is cited once, thus:

• • • • • 
          RFC2618 - HTTP Over TLS (HTTPS) (2.3 Security)

First, RFC2618 was superseded by RFC4668.

Second, RFC4668 doesn't mention TLS so it is unlikely to be correct."