"The Four Olds" (sijiu) – old ideas, old habits, old customs, old cultures – were discouraged and were replaced by Communist ideology, particularly during the Cultural Revolution.
四旧（四旧）-旧观念、旧习惯、旧风俗、旧文化都被摒弃，被共产主义思想所取代，尤其是在文化大革命期间。