Purge and Save or Purge and Exit from Clement Yiu are two command functions to purge drawings of unused applications and table elements. PF and PX perform the same function with different outcomes. The first command is a zoom out to the far extent of a drawing. Next, the Purge command is run twice — the first time to remove unused applications and the second to remove all unreferenced, named objects (layers, linetypes, and so forth). The last common operation is a quick save of the drawing after purging. At this point PF ends, but PX will continue by closing the drawing.