Regional Codes ...
For statistical purposes, the US Census Bureau has divided the country into four Regions. Dock is located in Region #3 (the South Region).
In turn, the US Census Bureau has further divided each Region into Divisions. Dock is located in Division #6 (the East South-Central Division).
The Office of Management and Budget (OMB) has created ten Federal Regions. Dock is located in Region IV (Region 4).
Referenced FIPS Records ...
FIPS Code: 01/20944 (Place Name: Dock)
County: Butler (FIPS State/County: 01/013)
Identifies a populated place (in this case, Dock) located wholly or substantially outside the boundaries of an incorporated place or CDP (Census Designated Place) but whose name has not been verified as authoritative by the U.S. Geological Survey (USGS).