The comprehensive @id3 v2 system for #MP3 metadata doesn’t seem to have an “explicit content” flag. I’m using an experimental XRAT frame (with a ‘1’ or ‘0’) for now, but I wonder if anyone’s already “solved” this in a better way?

Note for Future Dan: if you want Firefox’s picture-in-picture (popout video) mode to be available for videos of less than 45 seconds, the setting you need is media.videocontrols.picture-in-picture.video-toggle.min-video-secs. This is useful if you’ve got a playlist of multiple short clips (which reuse the same <video> element) that you want to treat as a single long video for the purpose of picture-in-picture.