-specified, then the aggregated cases replace the active file. Use of
-OUTFILE to write a portable file or scratch file is a PSPP extension.
+specified, then the aggregated cases replace the active file.
+Use of OUTFILE to write a portable file or scratch file is a PSPP extension.
+
+If OUTFILE=@samp{*} is given, then the subcommand MODE may also be
+specified.
+The mode subcommand has two possible values: ADDVARIABLES or REPLACE.
+In REPLACE mode, the entire active file is replaced by a new file
+which contains just the break variables and the destination varibles.
+In this mode, the new file will contain as many cases as there are
+unique combinations of the break variables.
+In ADDVARIABLES mode, the destination variables will be appended to
+the existing active file.
+Cases which have identical combinations of values in their break
+variables, will receive identical values for the destination variables.
+The number of cases in the active file will remain unchanged.
+Note that if ADDVARIABLES is specified, then the data @emph{must} be
+sorted on the break variables.