If Phone can be Put in 3 Modes

0. RUIM Mode
1. NVM MOde (Original Non Volatile MOde)
2 RUIM if available (means if RUIM Inserted then on RUIM or else using NVM Data)

I using in India with 3 Mode means in India use RUIM Card and while in USA Just Remove the RUIM Card and it will work as your Original Phone.