Classifying Different Object Types
You need a class type to create a class. The class type defines which object types you can classify in the class, for example only materials, or only documents.
However, when you create or maintain a class type in Customizing for Classification, you can define a class type that lets you classify objects of different types in the same class. This allows you to classify objects that are logically related to each other in one class.
A batch and the material for which it is created are logically related. For this reason, there is a class type for both batches and the materials to which they belong. In class type 023, the Multiple objs allowed indicator is set, and the object type 'material' is defined as an additional object type. If you create a material for which batches are required, you can classify the material and the batches created for it in one class.
In Classification
Displaying object types
When you display classified objects in the assignment functions, you can define which object types are displayed. To do this, choose
Extras 
Set object type. 
You see a list of object types that can be classified in the class type concerned, and can enter the object types you want to see on the assignment screen.
Classifying different object types
To select the object type you want to classify, choose
Extras Change object.
If different object types can be classified in a class, it is possible to set up an object hierarchy for the objects. This object hierarchy works like a class hierarchy (see Object Hierarchy ).