Below is welt placement along the welt pocket stitching guide.
Below you can see the two pocket bag pieces. One pocket bag piece is a cotton woven and the other pocket bag piece is the fashion fabric.
Above is the zipper placement, once you've cut open the pocket line and pulled in the pocket bag pieces.
So the end result is a welt pocket with a hidden zip. Yep, I've sewn in 6 zips. What was I thinking.