blacklist(3) on FreeBSD
The text 7bd27700a82c, as FreeBSD 13.5-RELEASE, FreeBSD 13.4-RELEASE, FreeBSD 13.3-RELEASE, FreeBSD 13.2-RELEASE, FreeBSD 13.1-RELEASE, FreeBSD 13.0-RELEASE, FreeBSD 12.4-RELEASE, FreeBSD 12.3-RELEASE, FreeBSD 12.2-RELEASE shipped it.
Blacklistd notification library