
If one of NUM, CAPS, or SCROLL.LOCK is checked, the corresponding LED will be shown on the applet.
If this is checked, when the mouse goes over an LED, a tool tip indicating the name of the LED will be displayed. It also enabled tool tips in the Preferences Dialog.
If this is checked, it is possible to bring up a popup telling the states of any of the LEDs by left-clicking on the applet.
If this is checked and if your X-server supports it, it is possible to toggle an LED by left-clicking on it.