I believe he is talking about the artificial casing that is on the oval shaped, water added, hams you get at any grocery store. I sliced up thousands of these when I worked in the meat dept., years ago.
These casings are usually punctured in spots, to let in a certain amount of the smoky goodness, but not very much.
I would definitely remove this wrapper, if I was going to re-smoke it. Although, there are some that don't have this casing. These are generally the more expensive hams too. IMO