Sirdar "The Essential Baby Pattern Book"

I bought this pattern book, there’ss a beautiful baptism/christening dress in there that I want to make. I have some parts of the pattern that totally be-fuddle me. Has anyone used this book, or got the book, so I could ask you my specific question. It mentions an over-lay and an under-lay made from stitches picked up on the neckline. This may be terms used in England that aren’t familiar here. What do those 2 terms mean?

I looked up over-lay and under-lay on Google, and what came up were sewing patterns, where there were pieces that overlapped, one being the overlay and one the underlay. I don’t know how much this helps, though.

I got an e-mail response from the company, thought it may help someone else if they come across this. The Underlay and Overlay form the button and buttonhole bands on the vertical edges of the back neck. So it’s really a knitted edge band.