It's MI if you were wondering. Think about it. That's an M followed by an I. That could be Minnesota, Mississippi, Missouri. Michigan should be MG. So why is it MI? I think they are trying to make people avoid sending correspondence to our state. Someone is about to send something, say an order of some kind. Then they think, what's the postal code for Michigan? Oh, forget it, I'll send it to another state. Thoughts?
I think it's pretty clearly explained here, that the labeling convention is inconsistent. However, I'm not sure why, if someone wants to mail someone in Michigan, that they would decide to "Oh, forget it, I'll send it to another state".
You should try the UK. This is just London. The problem is that an 'N' postcode is north London, which is in the south of the UK. Their is no map to work the country out, because it would be the size of a wall. Note EC and WC are also just central London The surrounding area. KT Kinston upon thames CR Croydon TW Twickenham, famous for rugby HA Harrow SM part of Surrey UB Uxbridge DA Dartford RM Romford Don't ask me the others, I don't have a clue All this, in a 20 mile radius