The alternative M-order is displayed here if the setting to create M-order from the stock order is configured. This is determined by the setting Create manufacturing order from stock order?, under the heading Automatic M-orders from Stock Orders under the Inventory tab in the Settings procedure.
In the same section in the Settings procedure you can also set this alternative as default using the setting Create M-order by default in Register Stock Order?. You can also select how the manufacturing order number and project number will be created.
If you have activated the setting Allow edit of M-order number on stock order row, under the same section as the setting above, you can also enter or select another manufacturing order number by using the PopUp feature or F4 in the field.
Please note that it is not possible to enter or select another manufacturing order number if you have activated the setting Show max quantity, under Requirements Planning under the Inventory tab in the Settings procedure. A "tooltip" is shown when moving the cursor over the M-order number field on the customer order row, which shows information about how to make it possible to edit the field.
Manufacturing orders are only created of parts on the stock order that are of type M (Manufactured). The manufacturing order will be created in the warehouse from which the stock order was sent. The user that creates the stock order must be part of a user group with permission to create manufacturing orders in the same warehouse.