You can share CF structures among applications. However, this results in all data being treated equally, which may not be desirable. If you want to treat all your RLS data equally, sharing CF structures might be an appropriate and relatively simple approach. However, if you want to give some data sets preference over other data sets, you might want to use several CF structures of different sizes. For example, you might place test data sets in a small structure and production data sets in a large structure. Or, to give CICS® data preference over DFSMShsm data, place the CICS data in a larger structure and DFSMShsm data in a smaller structure.