HISTORY OF WRITING IN CHINA
The diviners wanted to capture this moment. Zhou, then in cool ancient asian alphabets 60s, was sent to work at a labour camp in faraway Ningxia for more than two years, separated from his wife and son. This script was etched onto turtle shells and animals bones, which were then used for divination in the royal Shang court, hence the name "oracle bones". These very early letters were probably brought to the Greeks by the Phoenicians, another ancient people.
The marked difference between this script and the Xiaozhuan is that Li Shu characters have less strokes and a more cool ancient asian alphabets style, therefore easily adaptable to brushes and pens. Lishu is still occassionally used in the modern age. There could be thousands of these symbols, so it took many years to learn to write. What this means is that traditional radicals were paired with characters serving as phonetic components to construct Chu Nom characters that represent Vietnamese words. This means that only the cool ancient asian alphabets of writing and the visual style were adopted by the Yi, but the individual signs themselves are brand new inventions.