JP - Japan CP - China SP - Singapore 2U: 90g - 94g 3U: 85g - 89g G2, G3, G4 etc.... refers to racket grip size. Smaller the number, the larger the grip. This topic has been discussed here b4, you can do a search next time
The CP rackets are available on the newer rackets. The older China rackets were labelled CN. I'm not sure if SP stands for Singapore, some argue that it stands for South Pacific