Had to remind some folks today that making postal codes mandatory is not optimal.

They come in flavours of 3-10 numeric characters (which you can't treat as numbers) or 6-8 alphanumeric strings. And some countries/territories just don't use them at all.

Like people's names, best not to even try.

Image by Stadscykel - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=15948580

#PostalCodes #ZIPCodes #ServiceDesign

A single postal code may cover a whole country, a region, a single settlement or municipality, a district of a populated place, a range of streets, a single street, a range of buildings, a single building, a single company or other large user, a mailing address range, a military unit .... and even an ethnic group.

#postalcodes #10

Postal codes are basically space-filling curves, if you think about it.

Interesting article on the design behind the US's ZIP codes:

https://www.newspapers.com/image/207561765/?fcfToken=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJmcmVlLXZpZXctaWQiOjIwNzU2MTc2NSwiaWF0IjoxNjg4ODIxMjk4LCJleHAiOjE2ODg5MDc2OTh9.ABXvozoqx5LrfhM2Cd-RQhwfEokXnUwPAezS4b7wbbY

(And yes, it's "ZIP", not "zip" -- it's an acronym. Bonus magic internet points to anyone who knows what the acronym means without looking it up...)

#math #postalcodes #spacefillingcurve #geometry