+.It Fl v
+Raise logging level. This option is also passed to ssh.
+.It Fl B Ar buffer_size
+Specify the size of the buffer that
+.Nm
+uses when transferring files. Larger buffers require fewer round trips at
+the cost of higher memory consumption. The default is 32768 bytes.
+.It Fl C
+Enables compression (via ssh's
+.Fl C
+flag).
+.It Fl F Ar ssh_config
+Specifies an alternative
+per-user configuration file for
+.Nm ssh .
+This option is directly passed to
+.Xr ssh 1 .
+.It Fl P Ar sftp_server path
+Connect directly to a local
+.Nm sftp-server
+(rather than via
+.Nm ssh )
+This option may be useful in debugging the client and server.