I may be wrong on spec of exclude tab on attribute set. But want to confirm. I want to make ASI mandatory on all transaction where there is material move like movement, MR, Shipment etc and not on SO/PO. Now I set always mandatory and then add C_Orderline on exclude rule.
Now though on SO line, it is not mandatory, some time may need to tag ASI. But check in WPAttributeEditor for exclude, will not open ASI dialog and ever make ASI field blank when table is in exclude rule.
My understanding is that when it is in exclude, it should be excluded from mandatory.
Find attached patch.