I can use FM - CLAF_CLASSIFICATION_OF_OBJECTS to get class characteristics for an object (for example material record from MARA).
But what about another task?
What I need to use if I want to write any class characteristics for a material record?
My situation is - a have some ABAP z-tables containing material IDs (MARA keys) and set of characteristics for predefined class. What are transactions of function modules I can use to make correct changes for materials?