On the ribbon, go to Tools > Setups > Jobs and select RFC Types.
This screen allows the set up of different Return from Customer types. If Return Type is required for Customer Returns is ticked in Options > Job > Customer Returns, it is always required for customer returns. This involves selecting an RFC Type when adding a return from customer (via Jobs > Return from Customer).
This is a useful means of tracking why goods are being returned, and can form part of the company's quality record.
Using RFC types correctly, returns can be monitored by running a list on a specific RFC type over a specific time period.
Further information