data-sets is available in the B<types.db> file. See L<types.db(5)> for a
description of the format of this file.
-The I<OptionList> is an optional list of I<Options>, where each option if a
+The I<OptionList> is an optional list of I<Options>, where each option is a
key-value-pair. A list of currently understood options can be found below, all
other options will be ignored. Values that contain spaces must be quoted with
double quotes.
=back
+=head1 ENVIRONMENT
+
+The following environment variables are set by the plugin before calling
+I<exec>:
+
+=over 4
+
+=item COLLECTD_INTERVAL
+
+Value of the global interval setting.
+
+=item COLLECTD_HOSTNAME
+
+Hostname used by I<collectd> to dispatch local values.
+
+=back
+
=head1 USING NAGIOS PLUGINS
Though the interface is far from perfect, there are tons of plugins for Nagios.