Apartheid prohibited marriage across racial lines for most South Africans.
 The Immorality Amendment Act 21 of 1950 (as amended in 1957 by Act 23) forbade "unlawful racial intercourse" and "any immoral or indecent act" between a white and a black, Indian or Coloured person
The apartheid bureaucracy devised complex (and often arbitrary) criteria at the time that the Population Registration Act was implemented to determine who was Coloured

