The Khipu
Khipus (or quipus) were structured systems of knots used by the Inca people to communicate
and record
numerical records. A relatively small number of khipus survived the Spanish conquest
of
South America and by and large are now held in museums. Structural details of each
of these khipus have been
described in a database by the Khipu Database Project
1. I have drawn the entity model shown here to describe this structure.
You can think of this model as a modern meta description of an ancient database system.