It's more of a URL shortener. Users are assigned 7-digit alphanumeric code that macroexpands into full address on participating websites as well as on some paper application processes. There are few safety checks to prevent abuses, and linked address can be changed later when you move.

Many online address forms in Japan uses equivalent of ZIP code to do similar already, but the expanded address are as granular as ZIP codes - I always fill in the rest of the address, but if I think about it, the fractions of users who do religiously verify and clarify the addresses must be less than 100%. I suppose this code will initially solve that problem with minimal infra changes for both users and the PO.