By default, the horizontal ruler in the editor is not shown. You can specify whether to display it and you can also choose
its style - a default style or a mainframe style for which the ruler indicates COBOL area A/B. To do this:
In the IDE, click
Tools > Options.
Expand
Text Editor and then expand
Micro Focus COBOL.
Click
Margins.
Check
Show the ruler and then check
Mainframe style if you want the ruler to indicate the A/B area.