The Director of Census Operations has said that attending the biometric camps set up for preparation of the National Population Register (NPR) is mandatory for each citizen of the country, even if they have enrolled for Aadhar. An official release, quoting the Director, said here on Thursday those who had already enrolled for Aadhar had to bring the Aadhar enrolment slip or card to the camp. Their biometric data would not be captured for the NPR, subject to the condition that the details collected for the NPR tallied with those in the Aadhar slip or card. — Special Correspondent