CST-ADJ is an inventory-related transaction type resulting from a change in the cost of the item, to both record the moment of change as well as reflect the resulting change in inventory valuation to the GL.
Example, the item's cost was 10USD and there were 100 of them... inventory valuation shows total of 1000.
If a manual cost change is made that changes to say... 13... or, as result of a standard cost revaluation (unless there is a specific code for that, can't recall), then you will get the following transaction in GL.
Inventory Account 300
Cost Revalue Account -300
Accounts affected are typically available in control files, product line or product line inventory detail account.
This is needed to create record of change and keep balance to the GL.
In tr_hist, if you check the transaction before and after for that part (AND SITE) you will see that in 3.21 the costs have changed.
You can do a simple test in demo system by simply changing the cost. Just remember that in QAD cost is PART/SITE specific.
I hope this helps,
Luis GomezDelCampo, MBA
20 years consulting, developing, training and managing QAD (and other ERP)