A fantasy book by Dianna Wynne Jones called Charmed Life has a character named Julia, she uses magic by knotting and untying a handkerchief. In the kid's book series called Magic Tree House, the main character is given an enchanted string with three knots on it. With each knot he unties, the wind blows harder, he can also re-tie the knots to stop the wind.
As far as I am aware, the name of this 'technique' is not mentioned in either book. What is this type of magic called? Specifically, does this every show up in fairytales/stories/old literature and what do they refer to it as there in?