As used herein: “Employees” means any of the following employees of the Department of Education of the City of Baltimore:teachers; personnel concerned with the supervision, administration, and direction of the educational program and related services; and other employees whose positions require a knowledge of and participation in the educational program. “Employee organization” means any organization:which is authorized by employees, or any appropriate unit thereof, to represent them; and which has as its principal purpose the representation of such employees in presenting their requests to the School Board, the Board of Estimates, and the City Council with respect to their wages and working conditions. City Code, 1976/83, art. 24, §18(a) Ord. 67-1031