If you are writing to a file, it depends what you want to do with that file. If, later, you want the print output as described by your program when it wrote to the file, you need to keep the correct carriage-control characters in your file. You will see them in the first column of the output. For an underlined line, you will see the original headings, with one control-character, and the underlines as a seperate line with a different control-character. What I'm trying to make clear is that in a file you will see two lines. You won't in any way see a merged-undelined-output-line if you browse a file, or the spool dataset for that matter. To see the underline in action, you have to print (and subject to Robert's points).