Used only in Web Stores - Inventory stocking types which can be purchased via Web Store. Stocking type ‘O’ (Obsolete) can never be purchased.  However, ‘U’ (Use Up-Obsolete) can be purchased via the web site up to the quantity you have remaining.  Possible values are:

All inventory stocking types can be added to cart

Limited Only the selected inventory stocking types may be added to cart