A coupling (or a coupler) is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the track gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.
In shipping, break bulk cargo or general cargo are goods that must be loaded individually, and not in intermodal containers nor in bulk cargo as with oil or grain. Ships that carry this sort of cargo are often called general cargo ships. The term break bulk derives from the phrase breaking bulk—the extraction of a portion of the cargo of a ship or the beginning of the unloading process from the ship's holds. These goods may not be in . Break bulk cargo is transported in , , , , or . of items secur..