Comments may appear anywhere in a SAS program. This is also a comment statement. In the first form, the comment begins with an asterisk in the first column and ends with a semicolon. The first form is useful for writing a brief note to yourself about the program. The second form is useful for writing longer comments that extend over several lines.
Comments have several important uses.
They help you keep track of the steps you took to derive an answer. There may be modifications to the data or to the statistical analyses during a study. Comments can be used to note the history of the investigation. Very often, someone else will be using your program and will need assistance with understanding how you arrived at your answer.