The first letter to indicates if the tablet is a consumer of professional model. C means consumer. P means professional
C -> Consumer (example: CTL-472)
P -> Professional (example: PTH-660)
The first digit of the number Indicates the active area size of the tablet
4 -> small (example: CTL-472)
6 -> medium (example: CTL-6100WL)
8 -> large (example: PTH-860)