Use
You can enter activities that have been marked for indirect allocation (activity type category 3: manual entry, indirect allocation) or as non-allocable (activity type category 4: manual entry, no allocation).
Under indirect activity allocation, the activity quantity is distributed to the receiver cost centers according to their allocation bases (see also:
Indirect Activity Allocation).

When entering sender activities, you can enter activities for the following sender objects:

In a business organization, variable costs are incurred on a sales cost center for each product unit sold. These costs cannot be credited to a profitability segment using direct internal activity allocation. The costs remain on the cost center, unless you are using the Internal Orders component (CO-OM-OPA) or Profitability Analysis (CO-PA) which allow a credit to take place.
See also
Entering Sender Activities Displaying Sender Activities Reversing Sender Activities