The Federal Information Processing Standards (FIPS) numeric code for the county issued by the National Institute of Standards and Technology (NIST). Counties are considered to be the `first-order subdivisions` of each State and statistically equivalent entity, regardless of their local designations (county, parish, borough, etc.). Counties in different States will have the same code. A unique county number is created when combined with the 2-digit FIPS State Code.

Source: Handbooks
Identifier: 0100