Field help (WSTKTXT) 

The display of information related to stock availability depends on the setup of the Order entry transaction.
As for the document valuation, the display of the product availability is conditioned by the value of parameter SOHVALLIG - Order valuation on line (VEN chapter, MIS group).

If the product is not available, the message: ’XXX: Not available in stock' is displayed, followed by the possible first date of availability and quantity in stock unit and sales unit.