A common developer practice is to "comment out" a code snippet, meaning to add comment syntax causing that block of code to become a comment, so that it will not be executed in the final program. This may be done to exclude certain pieces of code from the final program, or (more commonly) it can be used to find the source of an error. By systematically commenting out and running parts of the program, the source of an error can be determined, allowing it to be corrected.