John,
The quick and dirty explanation is: Edit your code set style.
The assembly and corridor have a code set style assigned to them. First, identify the code set style that your corridor is using. Second, in the settings tab > multi purpose styles > code set styles, right click on the relevant code set style and select edit. Third, in the codes tab of the code set style dialog box, click the graphic in the appropriate cell under "Label Style" and select a label style. You can apply labels to points, links and shapes. When you are done click ok to close the dialog box, rebuild the corridor,and if you got it right the labels should show up in your section views.
There is more detail that I don't currently have time to get into, but hopefully this gets you pointed to the right direction.
See the attached screen shot.
Good luck.