Man pages matching name sysusers.d in section 5:

sysusers.d.5.de	debian 10 / manpages-de
sysusers.d.5.en	debian 10 / systemd
sysusers.d.5.de	debian 11 / manpages-de
sysusers.d.5.en	debian 11 / systemd
sysusers.d.5.de	debian 12 / manpages-de
sysusers.d.5.en	debian 12 / systemd
sysusers.d.5.en	debian 12 / systemd-standalone-sysusers