Abstract: A description is given of a container closure for filling and emptying containers, in particular drum-like transporting containers, which can be inserted in an exchangeable manner into a container opening, which receives a plug head. The container closure has a riser tube, which is connected to the plug head, and a removal connection element, it being the case that the latter can be locked to the plug head by means of a stud coding system which has coding studs and matching coding recesses. According to the invention, the coding studs are provided on a first securing part and the coding recesses are provided on a second securing part. One of the securing parts is designed as an annular disc, which can separately be fitted loosely, such that it cannot slip off, onto the modular removal connection element. The other of the securing parts is integrated in the plug head.