View source for Nvidia native driver brightness control with Leap 42.1

X11 driver detection seems to be fully automatic with openSUSE Leap 42.1: All the xorg.conf.d files are empty (except for input devices).
Thats fine, as long as everything works, but sucks if you try to fix something and there is no new documentation covering it.
But finally I found a place to enable brightness control:

I modified /etc/X11/xorg.conf.d/50-device.conf that only contained comments. It now looks like that:
 
 Section "Device"
   Identifier "Nvidia Device"
   Option  "RegistryDwords"  "EnableBrightnessControl=1"
 EndSection

still works with Leap 15.3 (using a 15.2 kernel)