Name | Description
:-------------------|:------------
-update\_win\_warn | If set, returns warning when important updates are available
-update\_win\_crit | If set, return critical when important updates that require a reboot are available.
-update\_win\_reboot | Set to treat 'may need update' as 'definitely needs update'
+update\_win\_warn | **Optional**. If set, returns warning when important updates are available.
+update\_win\_crit | **Optional**. If set, return critical when important updates that require a reboot are available.
+update\_win\_reboot | **Optional**. Set to treat 'may need update' as 'definitely needs update'. Please Note that this is true for almost every update and is therefore not recommended.
+
+
+In contrast to most other plugins, the values of check_update's custom attributes do not set thresholds, but just enable/disable the behaviour described in the table above.
+It can be enabled/disabled for example by setting them to "true" or "false", "1" or "0" would also work.
+Thresholds will always be "1".
+**Hint**: If they are enabled, performance data will be shown in the webinterface.
+If run without the optional parameters, the plugin will output critical if any important updates are available.
### <a id="windows-plugins-uptime-windows"></a> uptime-windows