When working with a clip's history, you can use one of three options: Keep Intermediates and Sources, Keep Sources, or Keep None. When you use Keep Intermediates and Sources, source and intermediate clips are embedded inside the clip history. This means that the frames used in the clip history are stored even if the intermediate clip (on the Desktop or in the clip library) is deleted. If this option is not selected, frames referenced by the clip history are deleted when the intermediate clip is deleted.
When you use the Keep Sources option, sources are embedded in the resulting clip with clip history but intermediates are not. Intermediates will no longer be available for clip history if you delete them. When intermediate clips are not available (either in the resulting clip with clip history, on the Desktop, or in the library), you cannot modify the clip's history using the Expand One button in Batch —intermediates are needed with this option. Instead, you use the Expand History button in Batch to expand the entire clip history back to the source clips. With Expand History, you modify the nodes corresponding to the intermediate processes rather than the intermediates themselves. See Expanding Clip History in Batch.
When you use the Keep None option, neither source nor intermediate clips are embedded in clip history. See History.