The R/W labels have to be attached to the section-section frame in the sheet style template that you are using to create your sheets.
Start a new drawing.
Use 'Sheet Manager' >'Sheet Styles' > 'Load Sheet Style' to bring the sheet style template into the drawing.
In the 'Sheet Manager' Menu, click: Sheet Styles > 'Create/Edit Frame'. Select the Section-Section Frame in the layout and Enter.
In the Dialog Box click the 'Text' button. You will see another dialog box.
In the second dialog box click the 'Add' button, and see another dialog box.
In that dialog box select "Cross Section: Right R/W" and click "OK". Click 'Add' again and select "Cross Section: Left R/W" and click OK.
In the "Edit Attached Text Labels" dialog box you will probably want to check the box that says "Draw Line Marker" for both the R/W labels.
Click OK to get out of your dialog boxes and, use the 'Sheet Manager' > 'Sheet Styles' > 'Save Sheet Style' command to save your changes, switch back to your project drawing and run the sheets again.
I hope that helps.