If you look into the No I'm Not A Human tag, you will notice that it is primarily filled with uploads that are part of a trend wherein artists draw other characters like they are guests at the door in-game... These posts are commonly tagged as crossover(but not always) which could be a good tag to exclude from a search if not for the potential of a fanart that is actually a NINAH character interacting with a character from another copyright which would also be excluded. I'm not really sure what it ought to be called, but I feel like some sort of trend or meme tag should be created so that it is easy to omit these types of posts when searching this tag.