In this subtitle the following words have the meanings indicated: “Accredited representative” includes: The representative of any labor organization, or its successor, authorized to act for the employees described in subsection (b) of this section; and A representative of the Maryland Classified Employees Association, Local 1935 authorized to act for the employees described in subsection (b)(2)(ii) of this section. As of December 31, 1983, “accredited representative” included only: The Amalgamated Transit Union, Division No. 1300; The Office and Professional Employees International Union, Local 2; and The American Federation of State, County, and Municipal Employees, Local 1859, Council 67. “Employees” means those employees who are validly represented by an accredited representative. “Supervisor” means an employee of the Administration who is a sworn police officer and who is in a career service position that: Supervises career service positions of a lower grade; Is supervised by an Executive Service position; and Has no authority to take personnel actions. The Administration shall bargain collectively and enter into written collective bargaining agreements as to wages, salaries, hours, working conditions, and pension and retirement provisions with the accredited representatives of its employees who are employed: In job classifications that on December 31, 1983, were included in recognized bargaining units pursuant to agreements in force on that date between the Administration and an accredited representative identified in subsection (a)(1)(i), (ii), or (iii) of this section; and In new or revised classifications comparable to those described in paragraph (1) of this subsection, provided, however, that supervisory, managerial, professional, confidential, including secretaries or assistants to administrative department and section heads or to other management staff personnel, and engineering classifications shall not be included; and As supervisors and sergeants in the Maryland Transit Administration Police. The Administration may provide its employees with automatic cost–of–living wage adjustments in accordance with any applicable formula in a collective bargaining agreement between the parties, provided that the aggregate of automatic cost–of–living wage adjustments provided to any employee in any contract year does not exceed 5 percent of the employee’s base wage rate as that base wage rate existed immediately prior to commencement of the contract year.