Man pages matching name rpc.idmapd in section 8:

rpc.idmapd.8.en	debian 10 / nfs-common
rpc.idmapd.8.fr	debian 11 / manpages-fr
rpc.idmapd.8.en	debian 11 / nfs-common
rpc.idmapd.8.fr	debian 12 / manpages-fr
rpc.idmapd.8.en	debian 12 / nfs-common