nsd-checkconf(8) on OpenBSD
The text 427f2282cdab, as OpenBSD 6.3, OpenBSD 6.2, OpenBSD 6.1, OpenBSD 6.0 shipped it.
NSD configuration file checker.
Flags it lists
-
-f -
-h -
-o -
-p -
-s -
-v -
-z