squid_unix_group(8) on Linux
The text d276967bdb1c, as Debian 7 (Wheezy), Debian 6.0 (Squeeze), Debian 5.0 (Lenny), Debian 4.0 (Etch) shipped it. The page shows this text now.
Squid UNIX Group external_acl helper
Flags it lists
-
-g -
-p -
-s