Yes, that's correct! The Incas, who ruled a vast empire in South America from the early 15th century until the Spanish conquest in the 16th century, used a unique system known as quipus (or khipus) for record-keeping and communication. Quipus consisted of sets of colored cotton or camelid fiber strings, with knots tied in various ways to convey information.
Each string could represent different categories of information, such as census data, tribute obligations, and inventory of goods, while the colors and types of knots provided additional meaning and context. Quipus were an essential tool for managing the complex administrative tasks of the Inca Empire, given that the Incas did not have a written language. Instead, they relied on this sophisticated system of knots to keep track of their extensive resources and populations. The study of quipus continues to reveal insights into Inca society, economy, and governance.