Manpage pcap-filter(7) is not installed on FreeBSD 12.0. It is referenced by tcpdump(1) and was present in FreeBSD 11.2-p4, but disappeared after binary upgrade to 12.0. It is missing on both my 12.0 machines.
It was this commit that stopped it being installed I think: https://github.com/freebsd/freebsd/commit/30f165e2d74c681f9df978d1f8f6eeef4569babb#diff-f47145dbca3572dd06e3bab12d4f176b
There are a few other pages that don't get installed. It's trivial to add them back - but I don't know if they were removed for a reason?
I attach a patch that adds in the man pages the libpcap distribution appears to install but the base system Makefile doesn't. They all seem of interest to libpcap users to me. I have also expanded the sed line to expand more macros found in the man pages.
Created attachment 204657 [details]