Man pages matching name systemd-backlight in section 8:

systemd-backlight.8.de	debian 10 / manpages-de
systemd-backlight.8.en	debian 10 / systemd
systemd-backlight.8.de	debian 11 / manpages-de
systemd-backlight.8.en	debian 11 / systemd
systemd-backlight.8.de	debian 12 / manpages-de
systemd-backlight.8.en	debian 12 / systemd