classification scheme

In metadata a classification scheme is an arrangement of kinds of things (classes) or groups of kinds of things. It is often represented as a hierarchical structure and accompanied by descriptive information of the classes or groups. A classification scheme is intended to be used for an arrangement or division of individual objects into the classes or groups. The classes or groups are based on characteristics which the objects (members) have in common. In linguistics, the subordinate concept is called a hyponym of its superordinate. Typically a hyponym is 'a kind of' its superordinate (Keith Allan, Natural language Semantics).