This is related to this meta-question about asking questions if you haven't read/watched the source material, but in reverse.
I don't think most people would be completely familiar with all the different aspects of Science Fiction and Fantasy, but would be pretty good at searching online resources and coming up with an answer based on their research.
Is it okay/permitted/allowed to answer a question if you are not familiar with the source material? Or is it frowned upon, and best practice is to rather allow someone who is well versed in the source material to answer?