The Inca civilization developed and used the quipu recording system.
A quipu, or khipu, consists of cords with knots, colours and positions that encode information. In the Inca Empire, trained specialists called khipukamayuq used quipus to record numerical data such as census figures, taxes, labour obligations and storehouse supplies.
The Inca state had no known conventional writing system like the alphabetic scripts of Europe or the hieroglyphic systems of Mesoamerica. Quipus therefore played an important administrative role across an empire that stretched along the Andes.
Most surviving quipus are numerical, using a decimal system in which knot positions represent units, tens, hundreds and higher values. Some researchers argue that certain quipus may have encoded narrative or linguistic information, but the full system remains undeciphered. Quipus should not be confused with the writing traditions of the Maya or Aztec civilizations.