Man pages matching name tcpdchk in section 8:

tcpdchk.8.ja	debian 10 / manpages-ja
tcpdchk.8.en	debian 10 / tcpd
tcpdchk.8.ja	debian 11 / manpages-ja
tcpdchk.8.en	debian 11 / tcpd
tcpdchk.8.ja	debian 12 / manpages-ja
tcpdchk.8.en	debian 12 / tcpd