Did you mean PIN or PID?
If you meant PIN, there can be two PINs for iLiad users. One is used to access iRex website, the other is used to access shell of iLiad. If you lost the first one, you have to contact iRex. If you forget the second one, it can be reset after reflash from CF.
Added:
Another PIN: to access your wireless AP.
BTW, I can't imagine the necessity to send iLiad back to iRex for lost PIN.