What if my fic crosses over more than one fandom but does not crossover with BtVS/Angel?
For the purposes of the site rules, such stories are counted as Non-Crossovers. Therefore you should first check that posting the story will comply with Rule 8. If so, you should tick the non-crossover checkbox when posting. You can either post in the Multiple Crossovers -> Non BtVS/AtS Stories category if you crossover with many fandoms, or post in the category for where your story is mostly set, and add the other crossovers as secondary categories.