The U.S. Patent and Trademark Office has rejected a request by Adidas to declare Nike's Flyknit patents unprotectable. The Big a argued that a person of ordinary skill in knitting would have been able to combined prior patents with generally known textbook writing on knitting to develop the Flyknit. While the technology used in Nike's one-piece upper is similar to that of a sock, the USPTO indicates that much of the engineering used to give different properties to different regions of the upper can be protected.