elsat on Nostr: ...

quoting nevent1q…emnt

For the curious out there: the address and the zip code in a letter are not redundant. The former informs WHERE to go, the latter informs HOW to get there. Each digit of the zip code maps to a USPS sorting center that your letter will pass through.

And the 4 extra codes that no one uses in the US refers to the last mile delivery route to your house.