Leading edge of any sail (main or jib, genoa) is the Luff. The bottom is the foot and the trailing edge is the Leech. The lower, forward corner is the Tack. The upper corner is the Head. The aft lower corner is the Clew.
The number that is stamped on your sail is the "Serial Number" I assume, since my DS II Sails (also Neil Pryde) have numbers stamped on them like that.