You might remember the alien language in the movie ‘Arrival’. One of our ancient cultures might have used code written in strings which has not yet been deciphered.
This raises a host of questions. Were these logosyllabic khipus a local phenomenon influenced by contact with Spanish writing, or do they have far-reaching roots in the pre-Columbian Andean past? Do the other types of khipus that were used in the central Andes until the 20th century, such as those for accounting, share features with phonetic khipus? What are the implications of a three-dimensional writing system, in which the sense of touch plays as important a role as sight, and how does this expand our understanding of what “writing” is?
Needull in a haystack 
I wonder how they correct misspelled knots
Interesting thought. I never thought about it.