ainsl(1) on Linux
The text a12a9f29ed99, as Debian 13 (Trixie), Debian 12 (Bookworm) shipped it. The page shows this text now.
AppendIfNoSuchLine
Flags it lists
-
-D -
-N -
-Q -
-a -
-h -
-n -
-q -
-s -
-v