Materials with Planning Type ND

Hi all,

For materials that are marked with planning type ND, while running MPS/MRP, there are planned orders created for the requirements created thru a Sales Order. On further investigation we found that the Item Category in the sales order item TAN has been assigned to planning types CP in our system in configuration settings VOV5 & VOV6.

What is the relation between these two and what is the basic settings in a standard SAP system for a material marked as ND?Which materials are usually marked for this planning type in a Plant?

Thanks and Regards in advance,

Deepak Prasanna S