-<p>When ngIRCd is compiled with debug code, that is, its source code has
-been ./configure'd with "--enable-debug" and/or "--enable-sniffer"
-(witch enables debug mode automatically as well), you can use two more
-command line options and two more signals to debug problems with the
-daemon itself or IRC clients:</p>
+<p>ngIRCd can log additional debug messages, which can be enabled with
+the command line option --debug (-d) or by sending the USR1 signal to
+the running daemon. Some of those messages may leak personal
+information, be very technical and can be very verbose. Therefore the
+debug mode is meant for troubleshooting only and should definitely be
+disabled during normal operation!</p>
+<p>In addition, a "protocol sniffer" can be enabled on build time by
+passing the "--enable-sniffer" option to the ./configure script which
+enables the "--sniffer" (-s) command line option (which is not available
+by default): this "sniffer" logs all incoming and outgoing IRC commands
+on all connections, which can be handy to debug problems with the daemon
+itself or IRC clients.</p>
+<p>Both modes are indicated in the version string shown by the IRC
+"VERSION" command: if the version ends in a dot (like in "26.1."), the
+daemon operates in "normal" mode (the version used in the example is
+"26.1"). If it ends in ".1" (like in "26.1.1") the "debug-mode" is
+enabled; and if it ends in ".2" (like in "26.1.2") the "IRC sniffer" is
+enabled, too.</p>