Historically, most of Vietnam were the settlement for Chams people with phonetic writing and language of their own [1]. They were very successful traders and So

Historically, most of Vietnam were the settlement for Chams people with phonetic writing and language of their own [1]. They were very successful traders and South China Sea was originally called Cham Sea [2]. Then they were displaced by the Nguyen Lords who considered themselves belongs to Han Chinese, and latter enforced Chinese based logographic writing system to the populations. Unlike phonetic, logographic writing system is neither effective nor it's efficient. In software engineering processing Japanese words is still problematic until now because of their usage of logographic writing system [3]. The are several movies and drama series documenting how the Korean moved from the Chinese logographic to Hangul phonetic writing system by their King Sejong to rapidly and significantly increase their literacy rates. [1]Đông Yên Châu inscription: https://en.m.wikipedia.org/wiki/%C4%90%C3%B4ng_Y%C3%AAn_Ch%C3%A2u_inscription https://en.m.wikipedia.org/wiki/%C4%90%C3%B4ng_Y%C3%AAn_Ch%C... [2]The Cham: Descendants of Ancient Rulers of South China Sea Watch Maritime Dispute From Sidelines: https://www.nationalgeographic.com/science/article/140616-south-china-sea-vietnam-china-cambodia-champa https://www.nationalgeographic.com/science/article/140616-so... [3]Sorting in Japanese – An Unsolved Problem: https://news.ycombinator.com/item?id=19628097 https://news.ycombinator.com/item?id=19628097