+.It Fl a
+In
+.Fl i
+or
+.Fl x
+mode,
+.Nm restore
+does ask the user for the volume number on which the files to
+be extracted are supposed to be (in order to minimise the time
+be reading only the interesting volumes). The
+.Fl a
+option disables this behaviour and reads all the volumes starting
+with 1. This option is useful when the operator does not know on which
+volume the files to be extracted are and/or when he prefers the
+longer unattended mode rather than the shorter interactive mode.