Here it is (can be better , but ...)
Regularly appears the message "Brightness" on a fugitive way
With the command dmesg |less it can be seen that it corresponds to an error message: Asus ACPI: Error reading brightness
After multiple research and tests, still not having succeeded in removing this message (or rather the cause of this message), I decided to deactivate the module asus_acpi which is not in /etc/modules (like sonypi, for example) but is integrated into the kernel.
David78 had advised me to add this module in the /etc/modprobe.d/blacklist file. But that did not function, the module did not deactivate from the memory when the system is launched. Also, I used another method automatically to discharge this module from the memory :
* I created an executable script with inside the command modprobe - R asus_acpi
* I copied this file in /etc/init.d
* Lastly, with the KSysV software, I set up the levels of initialization of script: number 99/start of a service for the levels of execution 2 to 5.
With regard to the deactivation, that it is in read-write memory or on disc (hibernation), it does not function absolutely, and all research or attempts which I made there did not change anything. Even when the deactivation is running, the PC does not manage to come out intact from this setting and it is necessary to start again. The reboot does not function either: it is necessary to shut down and restart.