Field help (DACBP) 

Flag used to define the position of this element in the invoice element entry grid in the BP record. This flag can take a value between 0 and 10.
The null value means that the user does not want to manage this element in the customer record.
In the opposite case, this flag must contain the position (line number) where the element must appear in the invoicing elements grid of the customer record.
When this element is displayed on the customer record, the default value is suggested and converted in the customer currency and can be modified according to the choice made for the Processing mode field.