It is probably time for you to learn that opening files that are CSV with a spreadsheet can change things. Your original file was comma separated and you wrote a data step to read a TAB delimited file, almost certainly because you copied cells from a spreadsheet. Dlm=',' with the file likely fixes lots of issues. We can tell such things as the file was comma delimited by reading the log: RULE: ----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0 4 'M',21.6,0.301 14 The bit between the "4" and the "14" is the actual content of the file read. You want to copy from the log and paste copied text into a text box opened on the forum with the </> icon to preserver the text formatting that SAS has in the log. I bet that if you look in your log that the 'M' for that line started on column 4 of the file with the first quote under the - character before the first + sign. The + occurs as position multiples of 5 characters, the 1, 2, 3 etc indicate column 10, 20, and 30 .   The main message windows on this forum reformat text, generally removing white space, so fixed column information from the line ruler above gets corrupted.     ... View more