+=item B<group=>I<field>[B<,>I<field>[...]]
+
+Chose the fields of the I<identifier> you want to group values by. Valid
+I<fields> are B<host>, B<plugin>, B<plugin_instance>, B<type> and
+B<type_instance>. In 99E<nbsp>% of all cases, you want to make sure all values
+have the same I<type> -- either by using a construct like C<type='^foo$'>
+or by adding B<type> to the B<group> option (e.g. C<group=type>).
+
+=back
+
+Example: Print the minimum, average and maximum time spent in each CPU state
+for all your web servers:
+
+ collectdctl show host="^www[0-9]\\." plugin="^cpu$" type="^cpu$" aggregate=min,avg,max group=type_instance
+