Consider 33042, "Summerland Key." This ZIP code covers several other Lower Florida Keys, including Cudjoe Key and Upper Sugarloaf Key. "Summerland Key" is technically correct, since the post office is on that island, but people on the other islands will _never_ write "Summerland Key" as their address, preferring instead to use the ("acceptable") name of their island instead. I'm sure this situation is not unique to the Florida Keys, and I therefore doubt the usefulness of resolving city and state from ZIP code outside of them there fancy big cities.