This command creates an Inverter button. An Inverter button is the converse of a Hiliter button: it hilites the area beneath it UNTIL you click on it. When you click it, it shows the area beneath unhilited until you release the mouse, at which point the button returns to hiliting the area again.
This is handy for creating dramatic white-on-black text, even in situations where you have no intention of clicking on the field to dehilite it. (If you want to be sure you don't accidentally do so, cover the Inverter button with a Vanilla button. Vanilla buttons are transparent and inert. Nothing will happen when you click on one (which in this case is just what you want).
