Auto-propagation to other segments = from the current segment to other identical source segments in the project
Auto-propagation to current segment = from another identical source segment in the project to the currently edited segment (transferring it right into the target segment box).
The function works across documents in a single project even when the documents are not glued, that is, you create a project choosing a folder with documents but you don't glue them virtually. Gluing in CafeTran is only virtual – you don't create any superglue file.
The multiple SDLXLIFF files project has a limitation for the Auto-propagation. It works only within one currently translated SDLXLIFF file (but not across all the files in the project). « no longer valid?
And:
The segments are immediately auto-propagated to all files in the project. Even when not glued!