Man pages matching name systemd-nspawn in section 1:

systemd-nspawn.1.en	debian 10 / systemd-container
systemd-nspawn.1.de	debian 11 / manpages-de
systemd-nspawn.1.en	debian 11 / systemd-container
systemd-nspawn.1.de	debian 12 / manpages-de
systemd-nspawn.1.en	debian 12 / systemd-container