I'm from the US and I skimmed past this post 6x before finally stopping and thinking about it because I had no idea what CO was. Although it's obvious in contex

I'm from the US and I skimmed past this post 6x before finally stopping and thinking about it because I had no idea what CO was. Although it's obvious in context if you're American, without context nobody would recognize state abbreviations, they're far too generic. MS ME MN MA etc could stand for so many things. I thought CO was "Chief Officer" at first.