ddns-confgen(8) on macOS
The text 90a03f875e59, as macOS 10.13.3, macOS 10.13.2, macOS 10.13.1, macOS 10.13 shipped it.
ddns key generation tool
Flags it lists
-
-a -
-h -
-k -
-q -
-r -
-s -
-z