This suggestion comes from Claus Lundstrøm and I just like to preserve his idea.

Many issues with RDLC Reports could be improved or be solved, if there would be one DataSet per Document in Document based Reports like Quote, Order Confirmation, Shipment, Invoice, Credit Memo etc.

My Details why: Currently customer facing Document based Reports cannot use Labels or Field Caption, because the Language could change between two Invoices, if you print more the one and these values are technical only transferred once per print.

Also, because Header (and Footer) have no proper Access to the DataSet (only First() and Last()) the fields values and captions have to be placed with Helper-Functions (SetData and GetData) to be shown correctly, when the next document in a batch print will be printed. In the Report Designer for many header fields you can’t say what the value will be, because in the Layout you just see < Expr > and if you look up the expression you see "Code.GetData(5,1)". Extending Header and Footer Fields is also very hard and prone to errors.