On the back of the orange-coloured form there is information of the kinds of things the government doesn't want coming into the country.
Titled "Articles Prohibited from Importation in Accordance with the law of the People's Republic of China", the list includes typical things as: arms, ammunition, explosives, counterfeit currencies, poisons, opium, morphine, heroin, marihuana [sic], fruits, vegetables, and food stuff and medicine from epidemic stricken areas.
It also adds these other items that people are not allowed to bring in:
Printed matter, films, photographs, gramophone records, cinematographic films, tapes (audio and video), compact discs (audio and video), storage media for computers and other articles which are detrimental to the political, economic, cultural and moral interests of China.
I don't know how gramophone records can be subversive, but did the government know gramophones are for sale at the Panjiayuan antique market? Or is it like Singapore where you can chew gum, but you just can't buy it?