A system of mathematical notation for string figures: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.738.2977&rep=rep1&type=pdf

Cited in a recent paper on string figures among the Awiakay people of New Guinea: https://www.academia.edu/44377116/Talking_about_strings_The_language_of_string_figure_making_in_a_Sepik_society_in_Papua_New_Guinea