Now, someone else can bring up the misapplication of “floating” knockout boxes.
314.23(H) Pendant Boxes.
An enclosure supported by a pendant shall comply with 314.23(H)(1) or (2).
(1) Flexible Cord. A box shall be supported from a multiconductor cord or cable in an approved manner that protects the conductors against strain, such as a strain-relief connector threaded into a box with a hub.
400.10 Pull at Joints and Terminals.
Flexible cords and cables shall be connected to devices and to fittings so that tension is not transmitted to joints or terminals.
FPN: Some methods of preventing pull on a cord from being transmitted to joints or terminals are knotting the cord, winding with tape, and fittings designed for the purpose.