Is there a codified definition of urban center? Because it’s not a term used by the census definitions; they define urban area. If your define non-urban center

Is there a codified definition of urban center? Because it’s not a term used by the census definitions; they define urban area. If your define non-urban center as one far from mass transit to defend the need for cars, it becomes circular logic. It’s probably better to refer to more official definitions, which already reference population density.