We have 2 machines that  are identical for the moment, we want to have a master folder for all the Parts, Assemblies and thier drw's, these will all be 0200-series numbers.  We have 2 machine folders, lets call them SFS-01 and SFS-02.  They contain all the Main assembly drw's, these will be 0300 and 0301-series respectively.   When a part for machine 2 needs to be modified and becomes rev. B how do we keep rev. A in the vault for machine 1 to use?  We don't want to have to give it a new drawing number, can PDM append the file name with a -A, -B etc.? or are we missing how to keep rev. A active?