The Framework remembers things between executions (e.g. the main Framework window size, location and layout).VLF-WIN
Find this information by searching for files with names like ppp_User_Virtual_ClipBoard.Dat and ppp_Framework_Virtual_ClipBoard.Dat stored in a temporary directory on your system (where "ppp" is the partition identifier). These files store virtual clipboard details between Framework executions.
They can be deleted at any time to clear the Framework's current virtual clipboard content. You may want to review The Virtual Clipboard.VLF-ONE
In VLF-ONE you can add logic to your application to clear the user and system virtual clipboards like this:
Also refer to the source code of DF_SLIDLB to see how this option is implemented: