A few month ago I have written about modularisation and the importance of programming in science. To get a little bit deeper into the topic, I will explain some further concepts in programming. One of them, which is especially important in modularised programs, are variable containers. The basic idea is that all variables, which are exchanged between the modules, are stored in a own module, which is then included into every other module. Nevertheless, some precautions have to be taken to make this concept a success in larger programs.