This event will be triggered when any key on keyboard is released. Please note that it is a global event (although its name has no "global" prefix). You can define its handler in any element, but you may need to check the focus before actually do something. The figure below shows how:
If you need to know which key is released in the event handler, you could use the "CURRENT_KEY_CODE" system property. The figure below shows how:
This event is available for page and all elements.