When databases contain large numbers of subsets, it is convenient to turn groups of them on and off at the same time. You can select ranges of subsets by clicking on the name of a subset using the left mouse button and dragging the mouse up or down to other subsets in the list while still holding down the left mouse button. Alternatively, you can click on a subset to select it and then you can click on another subset while holding down the Shift key to select all of the subsets in the middle. Finally, you can select a group of multiple nonconsecutive subsets by holding down the Ctrl key while you click on the subsets that you want to select.
Once you have selected a group of subsets, you can use the buttons at the bottom of the pane whose subsets you selected. There are two action buttons at the bottom of each subset pane. The top button applies an action to all of the sets in the pane regardless of how they have been selected. The bottom button applies an action to only the subsets that you have selected. Each action button has three possible actions: Turn on, Turn off, and Reverse. You can change the action for an action button by clicking on the down-arrow button to its right and selecting one of the Turn on, Turn off, and Reverse menu options. When you use an action button that is set to Turn on, the appropriate subsets will be turned on. When you use an action button that is set to Turn off, the appropriate subsets will be turned off. When you use an action button that is set to Reverse, which is the default action, the appropriate subsets' enabled state will be reversed.