A 27-year old woman just asked me what zip codes "do".
Bad answers:
1. It's your social security number, so they know who the letter is really from. Older people had shorter numbers, that's why you see some 5-digit and some 9-digit.
2. It's a special code that you're supposed to use to indicate whether or not your letter contains a terrorist plot, exhortation to sedition, or juicy letter-sex. The higher the number, the higher the "the NSA should open and read this" value.
3. We just make those up because otherwise it looks weird. Put anything you want. Instead of numbers, I just write "bacon!"
4. They indicate the priority of the letter. The higher the number you put on, the more "zip!" it gets going through the postal service.
5. If you can see those numbers, you have uncovered the alien pod-people conspiracy. They'll know you're onto them if you ever mail a letter or mention the numbers again. If I were you, I'd hide. And for God's sake, don't check your mail!
6. It's the number for the person living in that town. That's what the census is for; they count everybody so they know how many there are and where they live, and then when they go to deliver the letter they just count from the town line (starting at the northeast corner, moving clockwise and inside) until they get to the right person. You know your friend's number, right? No? Do you even know your own? It's a federal crime to throw out the letter telling you your number, because if you move, you have to swap it with whoever's house you're taking.
7. It's a
code. If I tell you, I'll have to kill you.
around her desk. It's probably the "most important" thing that's happened here so far this decade. These people...