-B. If the operating system supports setting all TCP sockets to keepalive
-mode by default, and possibly lowering the delay until keepalive probes
-start, enabling this configuration can protect against hangs through
-silently broken connections, but not against a malicious server.
+It is generally also advisable to enforce SSL certificate validation, by
+either using --sslcertck on the command line, or using sslcertck in a
+"default" configuration entry of the rcfile, or using sslcertck in
+each of the relevant individual poll descriptions of the rcfile.