The following words and terms, when used in this subchapter, have the following meanings, unless the context clearly indicates otherwise:
Double-head anchor (four bolt system)-Two anchor heads in the window frame on each side of the window made and installed according to this subchapter. Each pair of anchor heads shall be used simultaneously and not singly.
Window cleaning-The operation of washing, wiping or other methods of cleaning windows.
34 Pa. Code § 47.391