FIPS state codes were numeric and two-letter alphabetic codes defined in U.S. Federal Information Processing Standard Publication ("FIPS PUB") 5-2 to identify U.S. states and certain other associated areas. The standard superseded FIPS PUB 5-1 on May 28, 1987, and was superseded on September 2, 2008, by ANSI standard INCITS 38:2009.[1]
The codes are used in Geographic Names Information System, overseen by the U.S. Board on Geographic Names. The codes were assigned by NIST and each uniquely identified a state, the District of Columbia, or an outlying area of the U.S. These codes were used by the U.S. Census Bureau, the Department of Agriculture to form milk-processing plant numbers, some cash registers during check approval, and in the Emergency Alert System (EAS).
The FCC assigned additional numeric codes used with the EAS for territorial waters of the U.S., but these were not part of the FIPS standard.
The FIPS state alpha code for each U.S. states and the District of Columbia are identical to the postal abbreviations by the United States Postal Service. From September 3, 1987, the same was true of the alpha code for each of the outlying areas, with the exception of U.S. Minor Outlying Islands (UM) as the USPS routes mail for these islands indirectly.
Each of the various minor outlying islands that fell within alpha code UM had an individual numeric code, but no individual alpha code.
On September 2, 2008, FIPS 5-2 was one of ten standards withdrawn by NIST as a Federal Information Processing Standard.[2]
fips52 was invoked but never defined (see the help page).