Current List of ClassFP Codes 

ClassFP Code Class Code Description Associated Geographic Entity
C1 An active incorporated place that does not serve as a county subdivision equivalent Economic Census Place, Incorporated Place
C2 An active incorporated place that is legally coextensive with a county subdivision but treated as independent of any county subdivision County Subdivision, Economic Census Place, Incorporated Place
C3 Consolidated City Consolidated City
C4 Alternate official common name for an incorporated place Locality Point
C5 An active incorporated place that is independent of any county subdivision and serves as a county subdivision equivalent County Subdivision, Economic Census Place, Incorporated Place
C6 An active incorporated place that partially is independent of any county subdivision and serves as a county subdivision equivalent or partially coextensive with a county subdivision but treated as independent of any county subdivision Incorporated Place
C7 An incorporated place that is independent of any county County or Equivalent Feature, County Subdivision, Economic Census Place, Incorporated Place
C8 The balance of a consolidated city excluding the separately incorporated place(s) within that consolidated government Economic Census Place, Incorporated Place
C9 An inactive or nonfunctioning incorporated place Economic Census Place, Incorporated Place
M1 A military or other defense installation that is not entirely within a census designated place Locality Point, Military Installation
M2 A military or other defense installation entirely within a place Census Designated Place, Economic Census Place, Military Installation
U1 A census designated place with an official federally recognized name Census Designated Place, Economic Census Place
U2 A census designated place without an official federally recognized name Census Designated Place, Economic Census Place

CityType Code Definitions

Code Description
N Non Postal Community Name: Former Postal Facility 
P Post Office: Official post office branch.
U Urbanization: Specific to Puerto Rico.
B Branch: A postal facility that is not the main post office and is outside the corporate limits of a city.
C Community Post Office: a contract postal unit providing mail services to small communities.
S Station: A post office that is not the main office for a city but is in corporate city limits.
Z PO Box: Linked to a set of PO Boxes.
X Military: Linked to an APO/FPO Military base.