SAP Message VFRR041 - Source &1 &2 and target &3 &4 have different revenue recog. categories

Diagnosis
The source is a time-related revenue recognition item but the target isa service-related revenue recognition item. In time-related revenuerecognition, the system uses the source item to determine the revenuesto be recognized. The determining factors are the value and definedperiods for this item. All the other items do not influcence therevenue recognition process.

System Response
This message is for information purposes only. During revenuerecognition, both items are processed completely separately from eachother.

Procedure
Check your copying control settings in Customizing for the target tosource document. Ensure that the required revenue recognition processworks correctly for both items. In other words:
Are the document types and item categories correctly maintained?
Have the correct revenue recognition categories been assigned to thecorrect item categories?