A significant number of story-identification questions are tagged as science-fiction-genre or fantasy-genre. However, it is an incorrect use of the tag for specific stories as explained in the tag wiki:
Used for questions on the science fiction genre itself, including its tropes and conventions. Should not be used to categorize questions about specific works of science fiction.
This problem has been discussed before on meta.
Often these tags are incorrectly used by new users who don't know better and are simply trying to distinguish between works of science fiction vs. fantasy.
I noticed that we do not have tags for science-fiction and fantasy which could be used to distinguish science fiction vs. fantasy works as these users are trying to do. Should we add these tags and start using them? I would think that most users who attempt to tag their question as science fiction vs. fantasy would correctly choose the new science-fiction and fantasy tags instead of science-fiction-genre and fantasy-genre since they should better match what the user is already typing to add tags.
I found some very old discussions about adding science-fiction and fantasy on meta here and here. However, these discussions appear to predate the creation of the genre tags and they do not address the problem with the genre tags. I agree with the meta discussions that these are very broad tags, but the purpose of these tags would mainly be to drive users away from incorrectly using the genre tags.
EDIT: to avoid tags which are so broad as science-fiction and fantasy, maybe use something like science-fiction-story-id? Or rename the genre tags to something like science-fiction-tropes to better reflect the purpose of the tag?