There is no direct recruitment of Group B employees in Indian Railways and they are recruited by departmental promotional exams of Group C employees. Recruitment of Group A employees is carried out by the Union Public Service Commission Civil Service exam. Recruitment of Group C junior engineers and depot material superintendents is conducted by the Railway Recruitment Board. Group C employees are recruited by 21 Railway Recruitment Board or RRB, which are controlled by the Railway Recruitment Control Board (RRCB). Group D staffs are recruited by 16 Railway Recruitment Cells or RRCs.