The formal definition of a mainlander is someone living in Taiwan whose "native province" is not Taiwan. Native province does not mean the province in which one is born, but rather the province where one's father's "ancestral home" is. Until 1996, identity cards and passports in Taiwan contained an entry for native province. The removal of native province from identity cards and replacement with place of birth was motivated in large part to reduce the mainlander/local distinction.

вот это я понимаю общество с цветовой дифференциацией штанов. пишут в пашпорт "у моего деда была московская прописка", чтобы окружающее быдло знало свое место.