May be overridden by B<PluginInstanceFrom> option inside B<XPath> blocks.
Defaults to an empty string (no plugin instance).
+=item B<Interval> I<Interval>
+
+Sets the interval (in seconds) in which the values will be collected from this
+URL. By default the global B<Interval> setting will be used.
+
=item B<Namespace> I<Prefix> I<URL>
If an XPath expression references namespaces, they must be specified