Define a vital record specification with the minimum number of cycles or copies that should be kept for a matching data set. For BYDAYSCYCLE processing, DFSMSrmm sorts GDGs either by generation and version numbers or by creation order, based on the CYCLEBY operand of the GDG parmlib option. You can also use the DUPLICATE operand of the GDG parmlib option to specify how VRSEL processing handles duplicate generations. For BYDAYSCYCLE processing, DFSMSrmm considers all the data sets created in a single day to be a cycle.