Functions in joystick settings and X-Plane cmd strings

Hello, I am an absolute newbie to X-Plane and X-Plane plugins. Is there a direct correspondence between the default "Function" names in the joystick/keyboard settings and the X-Plane command name strings? Is it even a valid question to ask, in the sense that should a user/plugin developer need to know this kind of info? Perhaps it is already clearly documented somewhere, but I'm having trouble locating it. Thanks in advance.