This page is to help lost souls searching for the algoritm for calculating the the last digit (check digit) of the Identification Number of Ocean Ship Containers (according to ISO 6346).
After reading through everything on that topic that showed up on Google and Google-groups (spending several hairpulling days) we were unable to determine how exactly to compute the last digit (CRC?) of the 11 digit ( actually alphanumeric ) number.
All available information on the subject was several comercial products that can calculate it for you, one algorithm that was incorrect and a lot of sites that decided that the algorithm is to complicated to be worth mentioning (or attempting).
We wrote a program in java swing wich will clarify this misterious algorithm - sources are available as well as demo
feel free to use it as you please
(program was written in Netbeans so contact me if you need the .form file)