Those letters are region or country codes, and can usually be found on the top-level Yonex racquets following the serial number. The code doesn't imply country of manufacturing, it marks which country or region that particular was originally exported to. So why bother about this? Well, some argue that the CN/CP racquets are specially made for players on the Chinese national team, and have thus been through a better quality control than the others, which would justify their higher cost. Others argue that the JP (Japanese) racquets are the best. Others just remain generally sceptical to the whole thing.