If a connection is established with an SSL server then any data received
from the server is displayed and any key presses will be sent to the
-server. When used interactively (which means neither B<-quiet> nor B<-ign_eof>
-have been given), the session will be renegotiated if the line begins with an
-B<R>, and if the line begins with a B<Q> or if end of file is reached, the
-connection will be closed down.
+server. If end of file is reached then the connection will be closed down. When
+used interactively (which means neither B<-quiet> nor B<-ign_eof> have been
+given), then certain commands are also recognized which perform special
+operations. These commands are a letter which must appear at the start of a
+line. They are listed below.
+
+=over 4
+
+=item B<Q>
+
+End the current SSL connection and exit.
+
+=item B<R>
+
+Renegotiate the SSL session (TLSv1.2 and below only).
+
+=item B<B>
+
+Send a heartbeat message to the server (DTLS only)
+
+=item B<k>
+
+Send a key update message to the server (TLSv1.3 only)
+
+=item B<K>
+
+Send a key update message to the server and request one back (TLSv1.3 only)
+
+=back
=head1 NOTES
B<-www> nor the B<-WWW> option has been used then normally any data received
from the client is displayed and any key presses will be sent to the client.
-Certain single letter commands are also recognized which perform special
-operations: these are listed below.
+Certain commands are also recognized which perform special operations. These
+commands are a letter which must appear at the start of a line. They are listed
+below.
=over 4
=item B<r>
-Renegotiate the SSL session.
+Renegotiate the SSL session (TLSv1.2 and below only).
=item B<R>
-Renegotiate the SSL session and request a client certificate.
+Renegotiate the SSL session and request a client certificate (TLSv1.2 and below
+only).
=item B<P>
Print out some session cache status information.
+=item B<B>
+
+Send a heartbeat message to the client (DTLS only)
+
+=item B<k>
+
+Send a key update message to the client (TLSv1.3 only)
+
+=item B<K>
+
+Send a key update message to the client and request one back (TLSv1.3 only)
+
+=item B<c>
+
+Send a certificate request to the client (TLSv1.3 only)
+
=back
=head1 NOTES