AFAIK, in-the-same-universe is covered; Enola Holmes would be an example of a derivative work. There's a carve out for parody, which usually involves filing of

AFAIK, in-the-same-universe is covered; Enola Holmes would be an example of a derivative work. There's a carve out for parody, which usually involves filing off the serial numbers as well as making fun of the original work. But it's not my area of expertise.