+
+ For compatibility with previous @command{genfile} versions, the
+@option{--run} option takes an optional argument. If used this way,
+its argument supplies the command line to be executed. There should
+be no non-optional arguments in the @command{genfile} command line.
+
+ The actual command line is constructed by inserting
+the @option{--checkpoint} option between the command name and its
+first argument (if any). Due to this, the argument to @option{--run}
+may not use traditional @command{tar} option syntax, i.e., the
+following is wrong:
+
+@smallexample
+# Wrong!
+genfile --run='tar cf foo bar'
+@end smallexample
+
+@noindent
+
+Use the following syntax instead:
+
+@smallexample
+genfile --run='tar -cf foo bar' @var{actions}...
+@end smallexample
+
+The above command line is equivalent to
+
+@smallexample
+genfile @var{actions}... -- tar -cf foo bar
+@end smallexample
+
+Notice, that the use of compatibility mode is deprecated.