https://youtube-creators.googleblog.com/2017/03/restricted-mode-how-it-works-and-what.html?m=1

While the system will never be 100 percent perfect, as we said up top, we must and will do a better job. Thanks to your feedback, we’ve manually reviewed the example videos mentioned above and made sure they’re now available in Restricted Mode -- we’ll also be using this input to better train our systems. It will take time to fully audit our technology and roll out new changes, so please bear with us. There’s nothing more important to us than being a platform where anyone can belong, have a voice and speak out when they believe something needs to be changed. We truly appreciate your help keeping the YouTube community active and engaged on topics that matter to creators and YouTube fans alike.


https://www.engadget.com/2017/03/20/youtube-restricted-mode-lgbt/