The employees in the Parking Services Department at Prestigious University, a large private university in upstate New York, are attempting to organize a union. Some of the Parking Services employees are clerical workers who work in the Parking Office located in the campus Administration Building, while others work as parking lot attendants. The parking lot attendants work out of kiosks located in the various parking lots around the campus. The parking lot attendants control access to the parking lots by checking for appropriate parking permits. They also issue parking tickets to enforce parking regulations and call for tow trucks to take away cars that are in violation of the parking regulations. The union organizing the workers seek to have all the parking employees in one bargaining unit. The university administration claims that the parking lot attendants are guards within the meaning of Section 9(b)(3) of the NLRA, and must be placed in a separate bargaining unit. Are the parking lot attendants guards within the meaning of Section 9(b)(3)? Should they be in a separate bargaining unit? Explain your answer.