TLS with client authentication and specify \fBgssapi\fP or
\&\fBkerberos_v4\fP if you are using a protocol variant that employs
GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
-authentication. This option does not work with ETRN.
+authentication. This option does not work with ETRN. GSSAPI service names are
+in line with RFC-2743 and IANA registrations, see
+.URL http://www.iana.org/assignments/gssapi-service-names/ "Generic Security Service Application Program Interface (GSSAPI)/Kerberos/Simple Authentication and Security Layer (SASL) Service Names" .
.SS Miscellaneous Options
.TP
.B \-f <pathname> | \-\-fetchmailrc <pathname>
RFC 2033.
.TP 5
GSSAPI:
-RFC 1508.
+RFC 1508, RFC 1734,
+.URL http://www.iana.org/assignments/gssapi-service-names/ "Generic Security Service Application Program Interface (GSSAPI)/Kerberos/Simple Authentication and Security Layer (SASL) Service Names" .
.TP 5
TLS:
RFC 2595.