+\fB\-MCt\fP <\fIIP address\fP> <\fIport\fP> <\fIcipher\fP>
+This option is not intended for use by external callers. It is used internally
+by Exim in conjunction with the \fB\-MC\fP option, and passes on the fact that the
+connection is being proxied by a parent process for handling TLS encryption.
+The arguments give the local address and port being proxied, and the TLS cipher.
+.TP 10