buffchan(8) on Linux
The text 4001f35405ca, as Debian 11 (Bullseye) shipped it.
Buffered file-writing backend for INN
Flags it lists
-
-C -
-L -
-b -
-c -
-d -
-f -
-l -
-m -
-p -
-r -
-s -
-u