On US envelopes, forms, and maps, AK is the two-letter written code for the state of Alaska. Every American state has a pair of letters like this — CA for California, TX for Texas — so post can be sorted quickly. You write it after the city: Fairbanks, AK. People almost never say A-K out loud for the place; they say Alaska. You will also see AK on car plates and in drop-down lists. Though actually, the same two letters mean other things in other worlds — most students in Taiwan meet AK first as the rifle AK-47 — so you have to look at where it sits. Next to a city or a zip code in American writing, it is Alaska.