Board Thread:News and Announcements/@comment-26239285-20191122101158/@comment-26239285-20200112195742

Yes creators are meant to mark their videos, but if they have failed to do so, YouTube said they'll do it for them. Some channels are no longer active, some foreign speakers may not understand what they have to do, and I suppose some users might not bother. AFAICT YouTube is required after the legal settlement to treat child-directed videos differently and if the uploader doesn't do it, YouTube has to do it for them somehow.

They also have to allow for some channels fraudulently marking their videos as not child-directed which appears to be a realistic concern, so they need some kind of bot to at least find child-directed content. Given the host of problems YouTube's bots have created in the past, however, I expect misclassifications like this and the problems it creates to be fairly common.

Yeah I looked for an add-on too but couldn't find anything either. Firefox lets you manage bookmarks in menus so maybe that's a way to go, but I would have to go through hundreds of videos and bookmark them ...