An immigration police officer checks a renewed Taibaozheng, a passport-like document that carries the entry permits for Taibao, or Taiwan compatriots, in Lukou Airport of Nanjing, capital of east China's Jiangsu Province, Sept. 21, 2015. The electronic version of Taibaozheng, which is in the form of a card instead of the former paper form, is enabled on the Chinese mainland on Monday. The electronic Taibaozheng, which also serves as the certificate of identity during Taiwan residents' stay on the mainland, will bring more convenience for Taiwanese travelling between Taiwan and the mainland. (Xinhua/Li Xiang)