shield-trigger(8) on Linux
The text 9d4a21e6c22f, as Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it. The page shows this text now.
program used with pam_shield PAM module to manage ip blocking