I am trying the post an invoice to SAP using the F-47 transaction and using SHDB to record the transaction and learn how it works. I see there that sometimes BU and ZK BDC OK codes are used. I would like to understand the difference between them, but could not find any official documentation. Please, explain the difference between the two?
A BDC_OKCODE indicates which action is (will) be executed on a screen (things like save, back, exit etc). The BU code is used for a SAVE function (like in MM01 transaction). Sorry but I cannot recall to which function ZK maps to. Obviously their difference lies in the fact that they map to different functions. You can still find out which function each button utilizes by using System->Status->GUI status.