Liland, if I had the wherewithal, I'd look up and link to the thread wherein all the postal code abbreviations for the US were posted. Instead, I'll be a techno-eejit and repost here below. I'd like to point out that there are quite a lot of UK and Canadian abbreviations one can find on threads here as well, and many of us from the US have no idea what they mean either. In my mind, aint nothing but a thang.
Alabama = AL, Alaska = AK, Arizona = AZ, Arkansas = AR, California = CA, Colorado = CO, Connecticut = CT, Delaware = DE, Dist. of Columbia = DC, Florida = FL, Georgia = GA, Guam = GU, Hawaii = HI, Idaho = ID, Illinois = IL, Indiana = IN, Iowa = IA, Kansas = KS, Kentucky = KY, Louisiana = LA, Maine = ME, Maryland = MD, Massachusetts = MA, Michigan = MI, Minnesota = MN, Mississippi = MS, Missouri = MO, Montana = MT, Nebraska = NE, Nevada = NV, New Hampshire = NH, New Jersey = NJ, New Mexico = NM, New York = NY, North Carolina = NC, North Dakota = ND, Ohio = OH, Oklahoma = OK, Oregon = OR, Pennsylvania = PA, Puerto Rico = PR, Rhode Island = RI, South Carolina = SC, South Dakota = SD, Tennessee = TN, Texas = TX, Utah = UT, Vermont = VT, Virginia = VA, Virgin Islands = VI, Washington = WA, West Virginia = WV, Wisconsin = WI, Wyoming = WY