Hidden front

In Chinese Communist Party (CCP) jargon, the hidden front (Chinese: 隐蔽战线; pinyin: yǐnbì zhànxiàn, sometimes translated as "hidden battlefront", "hidden struggle" or "covert front") is a phrase that describes CCP espionage, including when the CCP was still an underground movement in mainland China before the establishment of the People's Republic in 1949.