A recording system need not copy the sounds of speech, as most writing does. Knotted cords can be signs that point straight at the things themselves, such as quantities, duties and people, through codes that have nothing to do with words. Writing that bypasses language is still a full way of keeping knowledge.
Recording who owes what does more than mirror a community from the outside. Each household's contribution is set down against its kin group, and each kin group's against the village. The act of keeping the record is one of the ways the community is performed into being and held together.
When people stop reading an old recording medium, it does not simply vanish. Its knowledge lingers in the living community's commentary and reshapes into new uses, such as reading the fall of the cords to foretell the future. Even a medium thought to have ended long ago can carry on in local, everyday forms.