in.ftpd(8) on Linux
The text 273297e26fb5, as Debian 3.0 (Woody) shipped it.
Internet File Transfer Protocol server
Flags it lists
-
-A -
-D -
-M -
-P -
-S -
-T -
-U -
-d -
-h -
-l -
-p -
-t -
-u