Just wanting to make sure I'm not missing something here, but nyankore seems to be a series of images drawn by one artist, in which case it should be the title of a pool rather than a general tag unless it's somehow a copyright of its own. It was previously accompanied by wankore for any image that had a dog-girl in it, but that looks like it got nuked already.
Plus, it sounds like a kinda doofy romanization, but I'm no expert there.