during interview, the IO had a big file on me, what's in it? they were all in a big folder, about half inch thick... I estimate maybe 40 to 50 pieces of paper... some looked really old. I was guessing that it was all the documents that they've had on me since I got me greencard many years ago. I didn't ask the IO, because the interview was going very fast and I was out with the green slip in less than 8 minutes.(according to the stopwatch on my watch)