1WEBVTT 2 3NOTE vertical spec: https://www.w3.org/TR/webvtt1/#webvtt-alignment-cue-setting 4 500:00:00.000 --> 00:00:01.234 vertical:rl 6Vertical right-to-left (e.g. Japanese) 7 800:02.345 --> 00:03.456 vertical:lr 9Vertical left-to-right (e.g. Mongolian) 10 1100:04.000 --> 00:05.000 12No vertical setting (i.e. horizontal) 13