68 Pa. Stat. § 953
The plane rectangular coordinates of a point on the earth's surface, to be used in expressing the position of a point in the appropriate zone of this system, shall consist of two distances, expressed in feet and decimals of a foot when using the Pennsylvania Coordinate System of 1927 and expressed in meters and decimals of a meter when using the Pennsylvania Coordinate System of 1983. For State Plan Coordinate System (SPCS) 27, one of these distances, to be known as the "x coordinate," shall give the position in an east-and-west direction, the other, to be known as the "y coordinate," shall give the position in a north-and-south direction. For State Plan Coordinate System (SPCS) 83, one of the distances, to be known as the "northing" or "N", shall give the position in a north-and-south direction; the other, to be known as the "easting" or "E", shall give the position in an east-and-west direction. These coordinates shall be made to depend upon and conform to the plane rectangular coordinates of the triangulation and traverse stations of the National Ocean Survey/National Geodetic Survey (formerly the United States Coast and Geodetic Survey) within the Commonwealth of Pennsylvania, as those coordinates have been determined by said survey.
68 P.S. § 953