New Delhi, Mar 4 (ANI): Union Home Minister P. Chidambaram on Thursday stressed for complete coverage of the population without duplication while preparing the National Population Register (NPR). Addressing the All India Conference of State Coordinators/ District Magistrates/ Collectors/ Deputy Commissioners on the subject of “Census of India 2011 and National Population Register, ” Chidambaram cautioned that special efforts would be required to ensure coverage of vulnerable sections of the society like the elderly, handicapped, weak and marginalized.