The product contains the most general information about a product. The product id, product name etc. 

Most of the more variable information about products is on a separate set of lists including: 

Sell prices are held on a list of product price levels allowing unlimited sell price levels. 

• Costs are held on a list of suppliers for the product. Allowing unlimited suppliers and different costs and units for each supplier, 
• Alternate codes such as bar codes are held on a separate list of alternate product codes. Allowing unlimited bar codes, supplier codes etc. for each product.