What is the purpose of ABSORPTION_TYPE column in CST_WORK_ORDER_COSTS table?

I'm writing a work order cost summary report and I see rows in the CST_WORK_ORDER_COSTS table with the ABSORPTION_TYPE column populated. I think I need to include those rows, at least for the work order cost, but not sure about including the quantities.

The majority do not have a value in the ABSORPTION_TYPE column. I'm seeing the values 2 and 3 in this column. Can you provide the meaning of those values?

The value 2 seems to be related to the Scrap cost type, and 3 is used for both Product and Component cost types.

Thanks in advance,

Joe