What does the flag Egcf_SkipExisting do when calling IEdmBatchGet.CreateTree?

The help file just says "Do not retrieve files that already exist in the local cache"

That would seem to imply that without this flag EPDM will retrieve all files to the local cache again, even if they already exist, but the IEdmBatchGet::ShowDlg call does not seem to be affected by setting this parameter.

Does this somehow affect what is transferred, even if the file is not marked as Get in that dialog?