Depending on your compensation plan, Order Sub Categories may or may not be necessary.  IDSTC will determine based on your system requirements if they are necessary.

Order Sub Categories are used for products that have specific effects on the compensation plan.  For example: when the inventory item is ordered, a  specific bonus is granted a qualification is met.  The default system order category is “None”.  All products can be set up in the None category and changed to another category if necessary.