nsupdate(1) on Linux
The text 93f788516cf8, as Debian 10 (Buster) shipped it.
Dynamic DNS update utility
Flags it lists
-
-D -
-L -
-P -
-R -
-T -
-V -
-d -
-i -
-k -
-l -
-p -
-r -
-t -
-u -
-v -
-y