A falling freight restraint system for trailers and cargo containers that prevents freight that is leaning against door from forcing the door open and possibly falling out, which could otherwise cause injury to the person who opens the door or damage to the freight. The addressing system facilitates data communications between a number of user devices linked to a data communications network. The Model is associated with a schema describing a limitation of the input value from the screen, and a check of whether the input value from the screen is in the correct form or not is performed collectively. The computer readable medium has pieces of media, at least one of which has a portion identified by a semiotic describer. The retainer has a plurality of radial teeth angularly oriented to engage a pipe and prevent its removal from the coupling.