(a) In all buildings, when an automatic passenger elevator is being serviced by an elevator maintenance company, elevator maintenance personnel or other persons and there are no maintenance personnel available to remain in the elevator car. "CAUTION" sign tapes shall be placed across the car door jamb. One strip of "CAUTION" sign tape shall be placed at a height of eighteen (18) inches from the car floor and another strip of "CAUTION" sign tape shall be placed at a height of fifty-four (54) inches above the floor.
(b) The "CAUTION" sign tape shall be three (3) inches in width with the words "CAUTION — DO NOT ENTER" repeated every six (6) inches. The lettering shall be black on yellow background. The letters shall be at least two (2) inches high.