2. Fish hands. In China's ancient poems, fish was regarded as the messenger of words, and the words were represented by "fish essence", "fish book", "carp" and "double carp".
3. Jade Bird delivers books. In the Southern Tang Dynasty, master Li Jing wrote a poem, "The bluebird doesn't spread the news outside the cloud, and the lilacs are sad in the rain"; In the Tang Dynasty, Li Bai wrote a poem "I wish I could repay Sauvignon Blanc because of three bluebirds". Li Shangyin wrote a poem "Pengshan has no way, bluebird, listen! -bring me what she said! " ; And Cui wrote a poem "When will the bluebird pass".
4. Biography of Huang Er. At present, there is no clear statement about the exact start time of carrier pigeon book transmission, but as early as the Tang Dynasty, carrier pigeon book transmission has become very common.