If you have a Nintendo-refurbished 3DS or 2DS, what are the letters and first 2 numbers of the serial number? I'm trying to write some code that can detect whether your system is refurbished. My refurbished American Old 2DS has AW91. I'm particularly interested in refurbished non-XL New 3DS systems, if they exist. The reason is that non-XL New 3DS devkits (IS-SNAKE-BOXes) are Y*91, and it would be weird if there were a collision on serials between retail and debug.