Everyone agrees khipu record numbers. Beyond that the field divides, and it divides on evidence rather than on temperament, which is what makes it a real dispute rather than a fashion.
One position holds that khipu are accounting and administrative devices, that the numerical content is the content, and that any narrative associated with a khipu lived in the memory of the specialist who kept it, with the cords serving as a mnemonic peg rather than as a text. On this reading there is nothing further to decipher, because nothing further was encoded. The other position, argued most fully by Gary Urton, holds that the structural choices available in the medium constitute a coding system capable of carrying more than quantity, and that some khipu are records of names, places or events in a form that could in principle be recovered.
Colonial testimony sits awkwardly across both. Spanish writers, including Garcilaso de la Vega and Bernabe Cobo, describe khipu specialists reading out histories, laws and confessional records, which sounds decisive until you notice that a skilled mnemonic performance from a numerical prompt would look identical to a reader who did not know the difference.
What would settle it is a matched pair: a khipu and an independent Spanish document recording the same content, close enough to align. A small number of candidate matches have been proposed and none is yet accepted as conclusive.