dpns-rmgrpmap(1) on Linux
The text dc3959b9b6de, as Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze) shipped it. The page shows this text now.
suppress group entry corresponding to a given virtual gid or group name