Reports residing in different applications can call each other in the SAP system using the Report-Report-Interface RRI. The term 'report' is used here as a generic term for:
ABAP report programs
Report Writer reports
EIS enquiry reports
Report book reports
The query is integrated into this interface. This means that queries can be called using this interface (receiver) and can themselves call other reports (sender). Before a query can be used as a sender or a recipient it has to be made known to the interface. Refer to the remarks on using the Report-Report Interface in Assigning Titles, Formats, and Notes.