QUOTE(getajob @ Aug 10 2015, 09:10 AM)
The U specifies the weight of the racquet. The lower the number, the heavier the racquet. 2U, 3U, and 4U racquets are common.
The G specifies the grip size. The higher the number, the smaller the grip size. G3, G4, and G5 racquets are common.
You are right on U but not entirely on G, Yonex G and other brand G is opposite.The G specifies the grip size. The higher the number, the smaller the grip size. G3, G4, and G5 racquets are common.