what does an "S" as second digit in s/n signify?
 

Hi..

random serial number question.. what does an "S" as the second digit on an iP4 serial number mean..

fwiw most serial numbers of any iPhone always begin 86, 87, or 88
I know that on 3G's and 3GS's a second digit "K" meant it was refurbished..

ran the s/n and it shows iPhone 4
warranty July 1, 2011
still has iOS 4.0 (so doubt its refurb as it was an early issue)

If you know what the "S" signifies please let me know!

Thanks in advance..