All subs with “-titles” in the filename just subtitle onscreen text that isn’t dubbed over. It can include the crawl, alien dialogue, and the text on those tractor beam controls in Star Wars. The point of them is so that you can watch with a dub and not have to be able to either read English text, or have an internationalized copy of the trilogy with a translated crawl and alien subs (such as our Krieg der Sterne preservation).
The Hindi dub is a little special in that I don’t actually know if the dub covers the alien dialogue. The copy of the dub I have (from a torrent) is missing many parts, including all of the alien dialogue, and these parts are in English until I can find a more complete source. I don’t plan on providing subtitles for the other gaps because I know those are supposed to be dubbed.