This switch to determines whether or not the column ruler appears at the top of each page in the listing output. This ruler is simply a line of information containing a string of alphabetic characters corresponding to each vertical column of listing information. The ruler reflects the current width, margins, and placement of the various listing columns at the time each page is printed, and helps the user to determine which column they are looking at. Turn this switch off if display of the column ruler is not desired.
┌────┬──────┬─────┬────┬──────────────────────────────────────────────────┐ │Type│Global│Group│File│Default │ ├────┼──────┼─────┼────┼──────────────────────────────────────────────────┤ │S │Yes │Yes │Yes │+Lr (show the column ruler in listing output) │ └────┴──────┴─────┴────┴──────────────────────────────────────────────────┘