At times during program processing, your program might have made changes to pages in the virtual storage window, and might no longer want to keep those changes. RESET, which is the opposite of SAVE, replaces data in the virtual storage window with data from the object. As with SAVE and MAP, the range to be reset refers to the object rather than the virtual storage. RESET resets only windows that are within the specified range, and it resets all the windows in the range that your program changed.
Do not specify RESET for a storage range that contains DREF storage.