The summary report by product presents two main transactional metrics whose accounting reference is the product reference:
-  : number of distinct product lines (unique references) in orders.
 -  : total units sold, all references combined.
 
An order contains 3 items:
- 2 units of product  (same reference)
 - 1 unit of product  (different reference)
 
 (2 separate references) (3 units in total)
  (in “exempted data collection” configuration)
-  → They are excluded from both the  and  columns
 
-  → They are also excluded from the two columns (  and  )