Apple has a database with all serial numbers and they use the last four bytes of the serial number to link to/open a support page. I have shared this kind of data in the past (*) but it was a pain to keep up with updates. I don’t have time for this, and thus I decided to push the data to a MacSerials repository on Github. Much easier to maintain this way.
The first update, with new data for the 5th generation iPad, is also available.
Have fun with it 😉