Long named options can be abbreviated to any unique prefix of their name.
.TP
\fB\-a\fR, \fB\-\-all\fR
-Wipe all unused space. This may take significant time.
+Wipe all unused space. This may take significant time. If the option
+\-\-unused-fast (or -U) is also present, the faster wiping method is used.
.TP
\fB\-b\fR, \fB\-\-bytes\fR BYTE-LIST
Define the allowed replacement bytes which are drawn randomly to overwrite
Show a list of options with a brief description of each one.
.TP
\fB\-i\fR, \fB\-\-info\fR
-Display details about unused space.
+Display details about unused space, without wiping anything.
.TP
\fB\-l\fR, \fB\-\-logfile\fR
Overwrite the logfile (update journal).
not to overwrite the space not written to since the previous wiping.
.TP
\fB\-v\fR, \fB\-\-verbose\fR
-Display more debug/warning/error messages.
+Display more debug/warning/error messages. This option may be used twice
+to display even more messages.
.TP
\fB\-V\fR, \fB\-\-version\fR
Show the version number, copyright and license of