What do you mean by taboo? What are the ways to avoid it? Please give examples separately.

Taboo is a unique historical phenomenon in China feudal society. "Taboo" refers to the names of emperors, "saints", officials and venerable persons. Usually, we must try to avoid or rewrite these words, which is called "taboo". There are three kinds of taboos: national taboos, family taboos and sage taboos. There are four ways to avoid taboo: a. change the word, such as changing "Qiantang" to "Qiantang" in the Tang Dynasty; B. function word method, (example omitted); C. word-missing method, which avoids writing the last word, (example omitted); D. Pronunciation taboos for addressing others in spoken language, such as Lin Daiyu reading her mother's "people" as "rice".