People in China have to have a lot of documents, from the government.
Besides National ID, Residential Permit Booklet (Hukou Booklet), which everyone has, there are two special documents that are interesting.
One is Pass for Travel to Hong Kong and Macau. That is a special document with the same format and content as a passport, but just for travelling to Hong Kong or Macau. Mainlander still needs a visa, but it is politically incorrect to call it visa. It is a notation, and you have to get it before you travel.
The other document is Pass to Travel to Taiwan. That document is specially created for Taiwan travelers, with similar visa mechanism, although people don’t call it visa. The interesting point is, since mainland claim owner of the Taiwan, traveler need to get a visa from the local Entry/Exit Administration to be admitted to stay in Taiwan for 15 days (a claim of ownership), and submit the same document to Taiwan to get another notation. Anyway, although it is a very complicate process, at least there is a process for individuals to visit Taiwan.
These documents are chained one after another. With National ID, Resident Permit, and photo, you get Pass to Travel to Taiwan. With that, you get Taiwan Visa by China, and with that, you get Taiwan Visa from Taiwan. It takes about a month to get everything ready.
I am going to get one, and have it ready. The freedom to travel feels so good.