Linguistic purism
(重定向自Ultrapurism)

Linguistic purism or linguistic protectionism is the practice of defining or recognizing one variety of a language as being purer or of intrinsically higher quality than other varieties. Linguistic purism was institutionalized through language academies (of which the 1572 Accademia della Crusca set a model example in Europe), and their decisions often have the force of law.