Runestone uses a YouTube API that broadcasts events when a reader interacts with a video. In this way, Runestone can record video-watching as an activity. As PreTeXt output we concede better behavior on small screens (“responsiveness”) to enable this feature in a Runestone version. A @label attribute is necessary for persistence in the Runestone database. Various PreTeXt features, such as playlists, are not yet supported—make a request.