What are Function buttons Attack 3 joystick?

All 11 of the buttons (including the "trigger") on the Attack 3 joystick can be considered as a "function button". The actual applicable function of each button on a Logitech Attack 3 joystick is completely software driven. Thus what happens when a button is pressed or any combination thereof depends on software and perhaps user preferences. A button that fires rockets in one game or simulation may change view or do something else different in another game/sim. Games/sims may even change what each button does on different vehicles in the same game/sim. Also note that not all games/sims may take advantage of every button available.