Field help (ABCCLS) 

The ABC category allows the classification of products with regard to their importance to the turnover or to the stock for example.
The ABC category is used as a selection criterion in the stock count lists.
Values between “A” and “D” can be entered manually or by update from the ABC statistical analysis, which can be set up. At the time of creation, the product is not associated with any statistical data and is classified in category “D” by default.