All Commonwealth census authorities have posed questions about identity in the millennium round of enumerations. The most controversial issue has been ethnicity. No universal definition or classification system has been devised and each of the 71 states and dependencies has tended to pursue the enquiry in virtual isolation from its neighbours. The attempt to describe the population in terms of race and ethnicity has been inherited from the colonial era. More recently the requirements of monitoring affirmative-action programmes in multicultural populations have resulted in the introduction or refinement of questions on these categories. A few states—a small minority of Commonwealth countries—remain hostile to such enquiries. Where the issues of race and identity are not pursued, questions of nationality, language, and religion often fill the gaps left, adding further refinements to the definition of identity. An examination of current questioning about identity in Commonwealth censuses reveals a highly complex picture.