Numpad keys managing backlight

They are /, *, –  and  + keys, combined with Fn key.

 Fn key + « / » allows you to loop through the different backlight modes. Not very useful on everyday use, except to discover the available modes.

 Fn key + « * » allow you to switch on or off the backlight.

 Fn key « – » and  « + » allow you to lower or rise the brighness of backlight.