That's a real good question. I'm not too familiar with the 4th gens, but sounds to me like it might be a cutout? I didn't realize there were only two open, but the best thing to do (without knowing whether you have an '09 or '10) is post that question here: http://www.ramforumz.com/forumdisplay.php?f=15 and see what others who have installed bed rails suggest. Good luck and if you need any more help, feel free to ask.
Nice of you to offer your assistance. I want to install side rails on my '09 Ram 1500 quad cab short bed...the kind that just go into the stake pockets. However, only the rear stake pockets are open...the front ones are just outlined. What do I do?