mac_seeotheruids(4) on FreeBSD
The text e00a5ed13752, as FreeBSD 15.0-RELEASE, FreeBSD 14.4-RELEASE, FreeBSD 14.3-RELEASE, FreeBSD 14.2-RELEASE, FreeBSD 14.1-RELEASE, FreeBSD 14.0-RELEASE shipped it.
simple policy controlling whether users see other users