Managing Your Work Environment > Setting Preferences > General Preferences >
History

Use these preferences to set clip history preferences.

Keep History Mode box
  Determines whether Sources or Intermediates and Sources appear on the Desktop when working with clip history.

Select: | To:
--- | ---
Keep Sources | Keep only the sources (clips without a history).
Keep Intermediates + Src | Keep both sources and references to all intermediate clips.
Keep None | Not keep any frames. If the intermediates or sources are deleted from the Desktop, they will be unavailable for the clip history as well.