2004 Cal.EC 400.10 Flexible cords and cables shall be connected to devices and to fittings so that tension is not transmitted to joints or terminals. Which I believe is refering more to connection to the appliances etc... But does this FPN cover this application. FPN Some methods of preventing pull on a cord from being transmitted to joints or terminals are knotting of the cord, winding with tape, and FITTINGS designed for the purpose.