The trouble is, the P1I doesnt' have the 3 letters that correspond to numbers on the keypad e.g. abc = 2, def=3 etc.
Instead on the 1 key is left press E right press R, on 2 left press T, right press Y
I first struck this when I called our own PABX and got an automated attendant asking me to dial the first 3 letters of the person's name. Of course without the letters above the keys it was somewhat hard to work out what number to dial for what letter.
That seems an amazing omission since I would have thought over 90% of phones worldwide have the letters above the numbers.