definition
strict definition
US Census GEOID
The identifier the US Census Bureau gives a place, formed by joining the two-digit state code to the five-digit place code.
A GEOID identifies a geographic unit in US Census data. For a place it is the state code followed by the place code, which together are unique across the country.
The join is what makes it unique. A FIPS place code repeats from state to state, so it identifies a place only once the state is known.
Leading zeros are significant and the value belongs in a text column. Stored as a number it silently becomes a different unit.