Man pages matching name networkd.conf.d in section 5:

networkd.conf.d.5.de	debian 10 / manpages-de
networkd.conf.d.5.zh_CN	debian 10 / manpages-zh
networkd.conf.d.5.zh_TW	debian 10 / manpages-zh
networkd.conf.d.5.en	debian 10 / systemd
networkd.conf.d.5.de	debian 11 / manpages-de
networkd.conf.d.5.zh_CN	debian 11 / manpages-zh
networkd.conf.d.5.zh_TW	debian 11 / manpages-zh
networkd.conf.d.5.en	debian 11 / systemd
networkd.conf.d.5.de	debian 12 / manpages-de
networkd.conf.d.5.zh_CN	debian 12 / manpages-zh
networkd.conf.d.5.zh_TW	debian 12 / manpages-zh
networkd.conf.d.5.en	debian 12 / systemd