Back in the days when most PC users lacked a mouse, people would make things to put over the F1-F12 keys (since those shortcuts tended to not be mnemonic) with

Back in the days when most PC users lacked a mouse, people would make things to put over the F1-F12 keys (since those shortcuts tended to not be mnemonic) with what each key did with various modifiers. e.g. https://www.ebay.com/itm/276317392496 https://www.ebay.com/itm/276317392496 It was a neat way of surfacing lots of commands without taking up any screen-space.