Return Unused Reserved Stock
ServiceVisit lets you release stock that was reserved for a Work Order but not used. You would use it when a job needed fewer parts than expected, or the visit was changed, so the unused quantity becomes available to other work again.
On the Work Order's inventory page you choose the item, the location and the quantity. The quantity must be greater than zero and cannot be more than is currently reserved at that location. ServiceVisit lowers the reserved figure and writes a Return movement that points to the Work Order. The on-hand quantity does not change, because the stock never left the location.
Return only applies to a reservation. Recording parts that were actually used is consuming them, which is a separate action.