Think of it as phone number buttons. There's the number, and all the letters are below it. That's exactly what this is. You can chat in numbers with your friends! Okay, I'll give you the numbers and what letters of the alphabet they represent. And they shall be waiting in the Notes and Credits. Some easy codes: 22-Hi 442-Omg 10015034-Facepalm
0: ABC 1:DEF 2: GHI 3:JKL 4: MNO 5: PQR 6: STU 7:VWX 8: YZ 9: SPACE