AFP viewer does not display changes specified in medium map
If you use the afpreorder utility to create or modify an AFP file, it might insert medium maps between pages. The AFP viewer does not apply these medium maps.
If you have the Preprinted Forms Replacement feature, the CombineAFPWithForm step turns on the Constant Back flag when a media object includes an electronic form for the back side and the medium map specifies simplex printing. Those constant back pages are not displayed in the viewer.