Hierarchy of classifications
The folder "Classifications" contains the hierarchy of classifications that can be chosen to classify objects.
The icon can indicate a classification 'parent' of other more specific classifications, a classification with no children or a container of other classifications. In the first case the classification is selectable, as its children, by clicking with the mouse; in the third case only the classifications contained can be selected. A classification with no children can be selected too.
Clicking on the icon the children of the generic classification or of the container are visualised; they can be, in their turn, further classifications or containers.