Yinrih are innately literate in the same way that humans are innately verbal. In order for this to work, kits have to be exposed to writing in the same way a human baby has to be exposed to language in order to acquire it.

For this to work, yinrih have to write a lot, and in a way that others can see. Perhaps there's a surface in every home and office that acts like a bulletin board or refrigerator door, where people leave messages for others to see.