The problem concerning how to treat illegal immigrants is now a very "hot" topic in the United States and in Europe. The definition of a word depends on your point of view. The words legal and illegal depend even more on your definition. And, furthermore, the definition itself is very "time" dependent and certainly limited by space or location. Who is authorized to define a word then? The answer is simple: whoever has the power at the time and the location! During our high school era, the words (1) "Taiwanese" and (2) "Mainlander" were defined loosely as (1) the people who had been in Taiwan two or more generations and spoke with Taiwan accents, and (2) those who had just escaped from Mainland China and moved because of the communist war. I said" loosely' because no one tried or was able to specify the terms properly. There was an artificial "gap" between these two groups of people. They rarely got together as friends; they generally did not like their children to get married etc.
Our high school class fought together for the first prize in the sports competition fiercely and without any problems. But, after the college entrance exam, all the people in the class were comparing the numbers of Taiwanese and Mainlanders who had been accepted at the various universities – especially the numbers accepted at National Taiwan University (Taida). I did not realize that we had this" gap" until I saw the pictures of the five "Mainlanders" who entered Taida, in various combinations, all of which were taken without a single Taiwanese from our class. One final question was my sister, who was born in Taiwan of mainlander parents, a Taiwanese of a Mainlander?