User Exit not supported in Higher verson
Have any one of you come across a situation where a working User-exit in lower version( like SAP 4.7 or ERP 2004) has been made obsolete in Higher version( Like ERP 2005)?.
And also is there any official communication from SAP that User exits interface(Parameters etc) never changed irrespective of versions.
Can some one please help me with some official link/document?. Or guide me a place to find the answer.
My customer is asking a proof also.