The rings have a manufactures mark to indicate which end goes up. Unless you have identified another mark as the up mark, this may be what it is for. Since the gap in the rings is what is used as a reference for the position of the rings, I wouldn't think it has anything to do with that. So as long as you have the correct side up, and the gap in the correct position, I would think you would be good to go.
2004 XT225 purchased new in October 2004 0 miles. Current miles over 26,000.