I don't understand compression but I have one area that reports having compressed on my Analyzer report (PGM=USNDRVR). I am saving a whopping 2% with compression (or maybe it means that 2% of my records are compressed?) I wonder, though, if compression might be a quick way to resolve a problem when I run out of space in an area. (If compression would save me anything, maybe it would buy me time to prep an unload/reload and expand an area.) I guess this assumes that compression is done at an area/file level.