Tattoolore

So I'm working on my 501st costume while working on my other first 501st costume...right? Anyway, working on seventh sister as I finally found a pattern that made me super happy with few adjustments to make this happen. I've been hording everything I needed for it, so I already have my fabric and armor printed (my garrison is great and keep asking when I actually be part of them and not just a handler/assistant to the group). But, as anyone know working on this thing for several years, it's changed so much and makes no sense on some things and the picture in the CRL doesn't even match the current requirements anymore, yadda yadda. So, while review the jacket requirements there is this line: "The jacket skirting opens in the back down the center." Can some one explain what exactly it means? I understand "jacket" "skirting" and "open" and "center" just not in this costume and context. I have not found any back center openings in the skirting or otherwise in this costume on any one let alone the animated character. What am I suppose to actually be doing here to my jacket?