# Classification

## How to Create a Class Hierarchy / Structure

| ### What to do:
| To work through this example, you must have completed the example Create a Class. In our class hierarchy example, the following hierarchy (structure) must be defined:
| Select Start > Classification > Classes. The Classes mask is opened.
| Find the class CLS-1000 Bolts.
| Select the Subclasses tab.
| To change to insert mode click .
| Change to the Class Code field.
| Click . The Classes list is opened.
| Select the class CLS-1100 Wood screws and choose from the context menu Take entry.
| To save the entry click . Now the class CLS-1100 Wood screws is a sub-class of CLS-1000 Bolts.
| Repeat steps 3 to 8 with CLS-1200 Machine bolts as a subclass for CLS-1000 Bolts.
| Highlight the subclass CLS-1200 Machine bolts. At the top of the list, the button is displayed. Using this button, you can display the selected record in the mask header.
| Repeat steps 3 to 8 with the classes CLS-1210 Hexagon screws and CLS-1220 Socket head screws as sub-classes for CLS-1200 Machine bolts.
| The structure of the classes can be viewed in the Sub-Classes browser ( Display Class Structures in the Browser).
| As soon as a class has supclasses assigned to it, the Container checkbox will be selected!
| It is not possible to assign CLS-1000 Bolts (superclass) to CLS-1100 Wood screws (subclass) as a subclass. The following message would be displayed in the message window.