Thank you. But this is not exactly what I want, because both $e->K and $e->N depend on the keyboard language. If I change my keyboard language /both on macOS and on Win32, for the same "physical" key I get different values. In this way I need to know beforehand the language of the keyboard to perform my new keyboard mapping. I was hoping that each key of the keyboard has a unique identifier which is bound with the hardware (also with the physical keys) and not change depending on the keyboard input language.