I am curious if there is a substantial difference between the 動物 and 音mad動物シリーズ tags that warrants them being separate? To me, the latter seem like an example of a tag which expresses that the theme is combined with Otomad/YTPMV, which is stated in the rules should be merged. However, since its a meta tag, I recognize there may be more to it that I am not seeing. I would like to hear thoughts on this matter.