So, how do we prevent political autobiographies from migrating out of the non-fiction shelves of libraries and bookstores (where they manifestly don't belong, and are probably quite unhappy) and moving into our cozy little corner? Should the Dewey decimal system be extended to cover works which own up to being fiction, with publishers putting 'genre' codes on their spines so authors who write several different styles get correctly fractionated (and for self-published, who decides?)? I don't frequent the horror shelves much, but should there be an immigration service preventing 'Mein Kampf' from joining?
My public library (he says proudly, having survived more than forty years without one) sticks little coloured labels on their books, so presumably somebody within the hierarchy decides 'Oh, this is historical fiction that contains magic, this is fantasy in a historical setting, and this is translation of myth covering this historical period. I only hope they don't do it by author 'Oh, my dear, Bradley. She's written Science Fiction!', since I can't see administrators actually reading all the books concerned. Most of them would clearly prefer to class all fiction under 'Childrens literature?', and be done with it. I suppose the system beats scanning along the shelves for any bright yellow covers with black printing, before retracing one's path alphabetically, spotting out authors one has read about in the review pages of New Worlds or Analog.
Any classification will be imperfect; the more detailed the focus, the less precise will be the separation.