37 Pa. Code § 42.3
The following words and terms, when used in this chapter, have the following meanings, unless otherwise indicated:
Light bar assembly-A device designed and constructed to display more than one steady burning, flashing or revolving beam of light with 360° visibility.
Marked police vehicle-A police vehicle that is equipped with at least one light-bar assembly and displays graphics, markings or decals identifying the agency or department on a minimum of three sides (front, rear, left or right).
Official identification-Identification issued, designated or approved by the individual law enforcement agency or municipality.
Official uniform-Any attire designated or approved by the individual law enforcement agency or municipality.
Unmarked police vehicle-A police vehicle not equipped with a roof mounted light-bar assembly. The vehicle may display graphics, markings or decals, identifying the agency or department.
37 Pa. Code § 42.3