A/HRC/28/64/Add.1 distribution, should facilitate development of policy and programme measures to improve the situation of minorities. 97. Census questions should allow open and multiple responses that enable respondents to self-identify according to their national, ethnic, religious and linguistic affiliation, including multiple identities. Ensuring accurate data for the most marginalized groups, such as Roma, is essential and should be facilitated through outreach and information for communities and training of census collection staff. 23