[supernova87a]

Is the incorrectly shared mail piece addressed to someone with a quite similar address, or potentially someone who previously lived there?

Just having thought once in a while about how complicated addresses are, I can only imagine all the things that can go wrong. (both for the post office, and for example, credit cards/banks that have to use addresses in validation of purchases, etc)

Imagine an apartment building with many units. Think of how people differently specify on the address lines which unit they live in? What if they leave off their unit #? What about apartments that are numbered "345 1/2 Second Street"?

What about a new person with the same last name that appears at an address? What do you do about that? Is an address that differs by a very subtle letter a different household? E.g. "345b Second Street"? Should you ship a package there or approve a credit card, or is that likely to be an attempt to fraudulently divert mail to someone else who is nonexistent?

I'm sure it's endlessly complicated, and I have no idea. But I know it will be complicated.

[user0648]

In industry parlance this is called piggybacking when two items are scanned/processed at the same time, leading to inconsistencies.