This was brought up today on my cloth diaper sewing board.
Those diapers where the legs appear to be turned and top-stitched, but the rest of the diaper is serged.
I don't really understand it, because it sure doesn't save time or effort like a normal serged diaper does. To me, I'd rather just T&T the whole thing. Anyway, some people really like the look and feel of them, so here is a basic simplified tutorial for them.
I used two SUPER-thin prefolds that were donated to me by a friend. They are only 2-4-2 but the size of regular prefolds... So, really, you'd need two anyway. I probably should have used two different colors of cotton fleece to really show this off, as the serging is hard to see with white-on-white.
First, you serge around from the start of where your turning hole will be until just to the first end-point of your leg-elastic. Then you serge again from the back end-point of your leg elastic, around the back, and to the other side's back end-point of the leg elastic... Leaving the areas where your leg elastic will be run un-sewn/serged.
Next... you turn the diaper inside-out.
Then, making sure to overlap your serging over all the end-points of the first side's serging, you serge just down those sides.
Then you turn inside-out AGAIN.
Then you just sew your elastic casings and install your elastic as usual. Then serge up the front as usual to close your turning hole.
I used my general M-L Fitted template for this.
Most of my templates are available for download and printing at http://prefold2fitted.blogspot.com/2012/10/online-free-downloads.html