"Zainichi" Koreans are ethnic Koreans living in Japan who trace their ancestry to migrants who had permanently settled there before the Second World War. When Korea was a Japanese colony, Koreans were considered to be Japanese subjects but this status was revoked by the Treaty of San Francisco in 1952. After normalization of relations between Japan and South Korea in 1965, the Japanese government granted permanent residency to "Zainichi" ROK nationals. Korean residents who were previously politically aligned with the DPRK switched their allegiance to the ROK so that they could acquire South Korean nationality and subsequently claim Japanese permanent residence. North Korea-aligned residents were later granted permanent residency in 1982. Both groups were reclassified in 1991 as special permanent residents (SPR), which granted the "Zainichi" near-total protection from deportation (except in the most severe cases of illicit activity) and expanded their employment opportunities. SPR status is specific to this class of individuals with colonial-era origins; more recent South Korean immigrants to Japan cannot apply for this type of residency.