Type Alias: TextTrackKind

TextTrackKind = "subtitles" | "captions" | "descriptions" | "chapters" | "metadata"

The five W3C TextTrackKind values. Video.js coerces any other (or missing) value to 'subtitles', which would surface a bogus entry in the CC menu, so EvePlayer.setSource rejects side-loaded tracks whose kind is not one of these.