From:
https://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-11/20260206082425Z/amd64/INSTALL.html#Features%20to%20be%20removed%20in%20a%20later%20release
The following features are to be removed from #NetBSD in the future:
- groff(1). Man pages are now handled with mandoc(1), and groff(1) can still be found in pkgsrc as textproc/groff.
- pf(4). This packet filter is obsolete and unmaintained in NetBSD. It will be eventually removed due to possible long-standing security issues and lack of multiprocessor support. New installations should use npf(7).
No 'npf mastery' book so I really need to read that man page...