This function, which can be accessed via a tunnel or a right click, makes it possible to specify the link to be created: if box "Direct order (1 to 1) mode" is ticked, the system will authorize the assignment of a sales order to a purchase order, for instance, but not the assignment of a sales order to several purchase orders (it must be 1 to 1).
This rule is applied upon requirement evolution (order update or creation).
If no rule is specified in this field, the rule specified in the DEFPTO - Assignment rule MTO parameter (STO chapter, SCH group) will be the one taken into account by default in the Automatic assignment, Automatic deassignment and WIP resynchronization functions.