[gambatte]

It might also help to know that Windows Mobile is the operating system but it is sold to wireless carriers that "modify" it to work on their systems. That is the AKU upgrade business, e.g. Verizon has provided a sanctioned update for the XV6700 but other carriers may not have any ROM updates. The 6700 is "end of life" and not supported anymore with ROM updates. That is why the kitchens were developed, so that we could get WM6 and 6.1 on our phones.