Ligature

Ligature is magic performed when one ties a string, thread, or cord of one or more knots. This is commonly used for binding spells. In Ancient Greek sorcerers used this method to bind wind to give sailors fair weather.

In Wicca tradition ones being initiated measure themselves with a cord from head to toe, then tie two or three knots to mark their first, second, and third degree of their progress. These knots serve as a magical binding preventing their energy from dispensing.

Facts came from: Pg. 274 of The New Encyclopedia of the Occult by John Michael Greer