I was looking through some things on the net when I came across a file download that had the format, XviD.Rets.avi. Now, I've seen videos in .avi as well as XviD, but not one like this. In fact, I've never heard of it, at least the "Rets" part. What the heck is up with it anyways? Also, why put one in this format when .avi alone is good enough?