FOR--Notes Using the IN and DO keywords IN and DO are not parameters, but they are required in the FOR command. If you omit either of these keywords, MS-DOS displays an error message. Using the replaceable variable To avoid confusion with the batch parameters %0 through %9, you can use any character for variable except the numerals 0 through 9. For simple batch programs, a single character such as %%F may be all that is necessary. You can use multiple values for variable in complex batch programs to distinguish different replaceable variables. However, you cannot nest (add) multiple FOR commands on the same command line. Specifying a group of files The set parameter can represent a single group of files or several groups of files. You can use wildcards (* and ?) to specify a file set. The following are valid file sets: (*.doc) (*.doc *.txt *.me) (jan*.doc jan*.rpt feb*.doc feb*.rpt) (ar??1991.* ap??1991.*) When you use the FOR command, the first value in set replaces %%variable (or %variable) and MS-DOS carries out the specified command in order to process this value; this continues until MS-DOS has processed all the files (or groups of files) that correspond to the value (or values) in set.