Use "Offline Movie Folders" for movie dummies?

Most of my movies, series are stored on an external Hard Disk, which is plugged in only for watching videos or editing (so whenn XBMC starts, when the HD is not plugged in the movie, series inforamation is lost).

And I have created dummies (which are stored in one folder), so real files with avi extrension (0 byte) with the names (the same like normal avi, mkv files) the movies / series of I have on my DVDs.

Should I add these folders to "Offline Movie Folders" or "Movie Folders" in the "Folders" tab.

Respectively, whatfor is this "Offline Movie Folders", I did not quite understand the explanation in the help file? When I try to let Media Companion scrape the dummies, it does nothing.