etcupdate(8) on FreeBSD
The text 1bb6f1fc43a9, as FreeBSD 11.3-RELEASE shipped it.
manage updates to system files not updated by installworld
Flags it lists
-
-A -
-B -
-D -
-F -
-I -
-L -
-M -
-d -
-n -
-p -
-r -
-s -
-t