[1] A quipu usually consists of cotton or camelid fiber cords, and contains categorized information based on dimensions like color, order and number.

[17] "The khipu were knotted-string devices that were used for recording both statistical and narrative information, most notably by the Inca but also by other peoples of the central Andes from pre-Incaic times, through the colonial and republican eras, and even – in a considerably transformed and attenuated form – down to the present day."

[4] His student, Manny Medrano, expanded on this connection, proposing that the manner by which cords were attached to the main body of a quipu could encode moiety affiliation.

After being contacted by local woman Meche Moreyra Orozco, the head of the Association of Collatinos in Lima, Hyland was granted access to the epistolary quipus of San Juan de Collata.

For example, Carrie J. Brezine decoded that a particular three-number label at the beginning of some quipus may refer to Puruchuco, similar to a ZIP code.

Making the matter even more complex, the Inca 'kept separate "khipu" for each province, on which a pendant string recorded the number of people belonging to each category.

[36] Historians Edward Hyams and George Ordish believe quipus were recording devices, similar to musical notation, in that the notes on the page present basic information, and the performer would then bring those details to life.

[37] In 2003, while checking the geometric signs that appear on drawings of Inca dresses from the First New Chronicle and Good Government, written by Felipe Guaman Poma de Ayala in 1615, William Burns Glynn found a pattern that seems to decipher some words from quipus by matching knots to colors of strings.

The August 12, 2005, edition of the journal Science includes a report titled "Khipu Accounting in Ancient Peru" by anthropologist Gary Urton and mathematician Carrie J. Brezine.

Performing a number of statistical tests for quipu sample VA 42527, one study led by Alberto Sáez-Rodríguez discovered that the distribution and patterning of S- and Z-knots can organize the information system from a real star map of the Pleiades cluster.

[40] Laura Minelli, a professor of pre-Columbian studies at the University of Bologna, has discovered something which she believed to be a seventeenth-century Jesuit manuscript that describes literary quipus, titled Historia et Rudimenta Linguae Piruanorum.

A more plausible candidate for the earliest known precursor to quipus may be the wrapped batons found at the site of Cerrillos from the Late Paracas Period (c. 350–200 BCE).

[46] The first undisputed evidence of quipu technology dates back to the Middle Horizon (c. 600–1000 CE),[47] with these early quipus being used by the Wari Empire.

Differing slightly from their Inca successors, extant Wari quipu specimens tend to be smaller, have brightly colored thread wrapped cords, and its own system of knots which scholars do not fully understand.

The quipucamayocs also tracked the type of labor being performed, maintained a record of economic output, and ran a census that counted everyone from infants to "old blind men over 80".

Inca historians used quipus when telling the Spanish about Tawantin Suyu history (whether they only recorded important numbers or actually contained the story itself is unknown).

"[51][52][53][54] Christian officials of the Third Council of Lima banned and ordered the burning of some quipus in 1583 because they were used to record offerings to non-Christian gods and were therefore considered idolatrous objects and an obstacle to religious conversion.

[55] While evidence for the latter is still under the critical eye of scholars around the world, the very fact that they are kept to this day without any confirmed level of fluent literacy in the system is testament to its historical 'moral authority.

'[56] Today, "khipu" is regarded as a powerful symbol of heritage, only 'unfurled' and handled by 'pairs of [contemporary] dignitaries,' as the system and its 'construction embed' modern 'cultural knowledge.

Anthropologists and archaeologists carrying out research in Peru have highlighted two known cases where quipus have continued to be used by contemporary communities, albeit as ritual items seen as "communal patrimony" rather than as devices for recording information.

[60] The villagers of San Cristóbal de Rapaz (known as Rapacinos), located in the Province of Oyón, keep a quipu in an old ceremonial building, the Kaha Wayi, that is itself surrounded by a walled architectural complex.

[57] In 2004, the archaeologist Renata Peeters (of the UCL Institute of Archaeology in London) and the cultural anthropologist Frank Salomon (of the University of Wisconsin) undertook a project to conserve both the quipus in Rapaz and the building that it was in, due to their increasingly poor condition.

[29] This was the first work to show how the Inca (Inka) Empire and its predecessor societies used the quipu for mathematical and accounting records in the decimal system.

The archaeologist Gary Urton noted in his 2003 book Signs of the Inka Khipu that he estimated "from my own studies and from the published works of other scholars that there are about 600 extant quipu in public and private collections around the world.

"[64] According to the Khipu Database Project[65] undertaken by Harvard University professor Gary Urton and his colleague Carrie Brezine, 751 quipus have been reported to exist across the globe.

One prominent patrimonial collection held by the Rapazians of Rapaz, Peru, was recently researched by University of Wisconsin–Madison professor, Frank Salomon.

[74] Quipus have been found with adornments, such dried potatoes and beans, attached to the cords, and these non-textile materials may require additional preservation measures.

The heating, ventilating and air conditioning, or HVAC systems, of buildings that house quipu knot records are usually automatically regulated.

If quipus are to be conserved close to their place of origin, local camelid or wool fibres in natural colors can be obtained and used to mend breaks and splits in the cords.

It was in quite good condition, with "brown cotton strings wound around thin sticks", along with "a series of offerings, including mysterious fiber balls of different sizes wrapped in 'nets' and pristine reed baskets.