Column MSGTYP in the ROOSGEN table contains RS* values

Hi,

Can someone tell me when the column MSGTYP will be filled with the value RS####? For example RS0073.

I see that for some datasources the value is RS#### and for the others the value is NULL. When does the system create on the SAP ECC system an entry in the ROOSGEN table with for example RS0073 as value for the column MSGTYP? I have put this question in SAP Neatweaver BW because I think that this is done from our BW system.

Greeting Raymond