Currently, we stop these invoices from posting by not having any automatic coding for negative qty deviations. Problem is however that our provisions are now created wrongly.

Therefore, we would like to add new document validation rules + validator:
1) a document validation rule for negative quantity
2) a document validation rule for positive quantity
3) a validator that really doesn't allow us to overrule the validation rule when a negative quantity deviation exist.

If these rules and validators are in place, we can use automatic coding for quantity deviations, so our provisions can be made correctly.