(H) dated June 12, 1968, the Ministry of Home Affairs informed all the other Ministries: "The undersigned is directed to say that in paragraph 6 of this Ministry 's O.M. No. 71/49/DGS (Apptt) dated the 11th December, 1949, it was laid down that all vacancies in Central Government Establishments, other than those filled through the Union Public Service Commission, should be notified to the nearest Employment Exchange and that no Department or Office should fill any vacancy by direct recruitment unless the Employment Exchange certified that they were unable to supply candidates." In office Memorandum No. 14024/2/77 Estt(D) dated April 12, 1977, the Department of Personnel addressed all the Minis tries/Departments and said, "As the Ministry of Agriculture and Irrigation, etc. are aware, in accordance with the instructions issued by the Central Govern ment (vide marginally noted communications), all vacancies arising under Central Government Offices/establishments (including quasi Gov ernment institutions and statutory organisa tions), irrespective of the nature and dura tion (other than those filled through the Union Public Service Commission), are not only to be notified to, but also to be filled through, the Employment Exchange alone and other permissible sources of recruitment can be tapped only if the Employment Exchange concerned issued a non availability ' certifi cate.