I'm looking at the Xkilt Manual(The 60 page version), and I'm a little fuzzy on just how this pleat under the apron is made. I'm looking at the pleating diagram appendix, and I see that there is 12" set aside for this pleat. Is this a box pleat like the rest, or is it just a knife pleat? It doesn't have the inner folds charted out like the other box pleats, which makes me think it may be a knife pleat. If It's a knife pleat, does it matter which direction it faces? Does anyone have any more detailed pictures of this pleat?

I do understand what that pleat is for, and I definitely want one on my next kilt. I just want to make sure I implement it correctly.