You can have just one or multiple blank space characters between values. The rwdc analysis program version 1.1 was updated to manage tab characters the same as blank characters. Using the original version 1.0, you would need to convert tabs to one or more blanks in your input file before processing. This can be done in the Context editor as a global search and replace command. Select Edit, Replace. Set the find string to \t. Check off the box for regular expressions. Hit the space bar a couple of times in the replace with field, then "replace all". Email me if you need addition clarification. - Mark Beyer, mbeyer@cessna.textron.com