This is what I've just noticed.
Then you can edit it only in the source segment editor (e.g. to add the edited source word to TM or glossary). The edition is not saved.
Then, what is the difference exactly between Edit Source Segments being selected and not? Only that when it's selected and you make changes in the source, the change is reflected in the source document too?
> the change is reflected in the source document too?
The change is reflected in CafeTran's project source segments (not in the original source document).