North Korea's hereditary system of classifying families by their political background and loyalty, which shapes where people may live, what work and education they get, their rations and whom they may marry.
In more detail
Songbun (literally 'ingredients' or background) grew out of loyalty investigations in the late 1950s and 1960s. Robert Collins describes three broad classes (core, wavering and hostile) subdivided into some 51 categories; in 1958 Kim Il Sung put their shares at 25, 55 and 20 percent of the population. Status passes down the family line, so the descendants of landlords, collaborators, defectors or political prisoners inherit disadvantage. The UN Commission of Inquiry (2014) found that songbun had been the most important factor in allocating housing, jobs, university places and food, and that marketisation and money have since complicated its effects.