The apropos(1) manual page has a HISTORY section. It mentions everything except FreeBSD (2BSD, 4.3BSD, OpenBSD). The history of apropos(1) in FreeBSD 1.0 to FreeBSD 10 is missing.
A commit references this bug: Author: gbe Date: Tue Jun 30 18:08:59 UTC 2020 New revision: 362809 URL: https://svnweb.freebsd.org/changeset/base/362809 Log: Mention FreeBSD in the HISTORY sections of apropos(1) and makewhatis(8). PR: 223520, 223521 Reviewed by: bcr (mentor) Approved by: bcr (mentor) Differential Revision: https://reviews.freebsd.org/D25521 Changes: head/contrib/mandoc/apropos.1 head/contrib/mandoc/makewhatis.8
I mentioned FreeBSD in the HISTORY section of apropos(1) and upstreamed the change to OpenBSD.
A commit references this bug: Author: gbe Date: Tue Jul 14 12:02:31 UTC 2020 New revision: 363178 URL: https://svnweb.freebsd.org/changeset/base/363178 Log: Revert r362809: Mention FreeBSD in the HISTORY sections of apropos(1) and makewhatis(8). We don't mention the first appearance of a utility in FreeBSD, when it first appeared in a BSD version that predates FreeBSD. PR: 223520, 223521 Reported by: rgrimes, imp Reviewed by: bcr (mentor) Approved by: bcr (mentor) Differential Revision: https://reviews.freebsd.org/D25521 Changes: head/contrib/mandoc/apropos.1 head/contrib/mandoc/makewhatis.8