53 Pa. Stat. § 22780
The city planning commission shall receive and keep on file an exact copy of each subdivision plat approved by it and of each plat made by it as adopted or modified by council as provided by section seventeen of this act. The commission shall also cause to be made or received by it a plat showing the location of any street accepted by council as provided by section fourteen of this act. The commission shall also obtain a map or maps or plat or plats of all streets established by law or officially approved previous to the taking effect of this act. All these plats or maps shall together constitute the official street map of the city. The placing of a street upon the official street map shall not in and of itself be or constitute an acceptance of a street or give to the same the legal status of an accepted street of the city.
53 P.S. § 22780