sftp-server(8) on macOS
The text 5ab1a999dfff, as Mac OS X 10.8.5, Mac OS X 10.8.4, Mac OS X 10.8.3, Mac OS X 10.8.2, Mac OS X 10.8.1, Mac OS X 10.8, Mac OS X 10.7.5, Mac OS X 10.7.4, Mac OS X 10.7.3, Mac OS X 10.7.2, Mac OS X 10.7.1, Mac OS X 10.7 shipped it.
SFTP server subsystem
Flags it lists
-
-R -
-e -
-f -
-h -
-l -
-u