+Leaves IP-addresses as they are. The deepest subdomains containing numbers have
+those numbers removed. So C<dsl-084-056-107-131.arcor-ip.net> becomes
+C<dsl-*-*-*-*.arcor-ip.net>.
+
+=item I<medium>
+
+Removes the last byte from IP-adresses. So C<84.56.107.131> becomes
+C<84.56.107.*>. Hostnames have the deepest subdomains removed if they contain
+numers, so C<dsl-084-056-107-131.arcor-ip.net> becomes C<*.arcor-ip.net> while
+C<shell.franken.de> is not modified. This is the default and recommended
+behavior.
+
+=item I<hard>
+
+Handles IP-addresses as I<medium>. Hostnames have all subdomains removed, so
+C<p5493EC60.dip.t-dialin.net> becomes C<*.t-dialin.net> and C<shell.franken.de>
+becomes C<*.franken.de>.
+
+=back
+
+=cut