For a while now I've been wanting to do a rating system that I can use for my videos. I didn't want to use the standard rating system that movies use, so I decided to use my own. It uses some things from the ESRB descriptors, but other than that it's really up to you which video is considered what, to a limit of corse. I also created a template for other people to use if they so wish to.
It has three different ratings, E - everyone, T - teens, and A - adults. It has an editable list that you can change to list anything you really want. I'm using my descriptors listed here. Feel free to download and use it for any of your needs. It's CC0.