Imagine inputting: "IiIIil" but meant to input "IiIIi1"
Oops now my package is going to Joe Blow on the other side of the country.
That’s probably why.
If my password manager has an option to not use similar looking characters when generating a password, it should be trivial to do the same for this system.
25^7 is 6 billion, and there are fewer than 200m people in Japan. That's enough for one character to essentially be error correction.
25^6=244,140,625 - I think I have seen estimates of 100,000,000 addressable entities in the Japan postal address system (a bit half of them being households, the rest companies,public buildings, various organizations and so on )
TFA says "seven-digit combinations of numbers and letters".
Yes absolutely. But my comment was just to confirm what you were saying about 25^7 (with one control digit) i.e. 25^6 would be enough to cover everything that is addressable in the system today. If we increase that to alphabet+ numbers 35^6, it is even more feasible.
Given that this is Japan, they probably just mean digits 0-9, which are quite often rendered that way rather than 一 to 九.