Let us find out the smartform that is assigned to a delivery document. First go to tcode VL03N and enter a delivery document number.
Select the menu Outbound Delivery –> Issue Delivery Output.
Note down the output type for which we want to find out the smartform name, ZKER in our case.
Now go to tcode NACE.
Select the proper application type, V2 (Shipping) in our case and click on output types in application toolbar.
Select the required output type i.e. ZKER and double click on processing routines.
Find the smartform name for medium 1 (Print output).