SMOKE uses a 6-digit integer code to identify a country, state (or province), and county (or other region) for a particular source. Most U.S. inventories input to SMOKE have the 5-digit U.S. Federal Implementation Planning Standards (FIPS) state and county codes. All inventory input formats have been adapted to include a special header record with which you can specify the country, effectively allowing the inventories to be provided with the 6-digit code that SMOKE uses. The 6-digit system was designed for use in the United States with states and counties, as well as Canada and Mexico, but it can be adapted for other uses. The format used by SMOKE for the codes is:

The SMOKE installation is set up to use U.S.-centered codes as defined in the COSTCY or the GEOCODE_LEVEL4 (if USE_EXP_GEOCODES Y) file, which contains the codes and their associated names and time zone settings. In this file, the U.S. country code is zero, which allows the U.S. country/state/county codes to be the same as the FIPS state/county codes that appear in U.S. inventories. See Section 6.10.2, “COSTCY: Country, state, and county names and data” for more information on the COSTCY file format.

To change the meaning of the country, state, or county codes in SMOKE, the COSTCY or the GEOCODE_LEVEL4 (if USE_EXP_GEOCODES Y) file must be modified to use different names associated with each country, state, county or tribal number. All SMOKE input files must also use this new numbering scheme, including inventory files and cross-reference files.

Acceptable values in SMOKE for the country code are 0 through 9. Acceptable values of the state code are 1 through 99. Acceptable values of the county code are 1 through 999. No alphabetic codes are accepted, since SMOKE stores these values as integers.