The Lock Options selection criteria will help determine the name of the plan set that the source is to be copied to.  The following two options are available:

• Same Plan Set Name - When this option is selected, the 'working copy' being created will have the same name as the 'Source' plan set and assigned the next available "version".
    
• Different Plan Set Name - When this option is selected,  the 'working copy' being created will have the specified name (selected from the drop down list) and assigned the next available "version".
  
  The drop down list will include all active plan set names (as defined on the Admin >> Setup >> Plan Set Names screen).

If a project has no plan set defined matching the Source plan set name, one will be created having a version of 1.  If a project has a particular plan set name, the working copy created will be assigned the next available version for that plan set name.