It was 50 years ago that the USPS debuted the zip code and it went over like a lead balloon. So they came up with a zip code character: Zippy. And then there’s this video. Yes, it’s long, but it’s got a lot funny/lame moments in it.
I learned the first number of the zip code is the region that you live in, the next two numbers are your subregion, and the last two numbers are your post office number. So, in Champaign, our region is 6, subregion 18, post office number 21.