It mean, that you not supposed to sew the zipper tape fabric all the way through the top edge, but at 1 inch mark, slip the zipper off, so you will have about 1 inch on each side of the top Ashe without the zipper tape sewn in.
I just check and I don't see any pending request. Can you provide your full name as on FB and I can check if you are a member. Or try again and I will make sure to approve.
