Yan'an Rectification Movement
The Yan'an Rectification Movement (simplified Chinese: 延安整风运动; traditional Chinese: 延安整風運動; pinyin: Yán'ān Zhěngfēng Yùndòng) was a political mass movement led by the Chinese Communist Party (CCP) from 1942 to 1945. The movement took place in the Yan'an Soviet, a revolutionary base area centered on the remote city of Yan'an.
Source: Wikipedia — Yan'an Rectification Movement (CC BY-SA 4.0)