@joyR
If you edit it, it is NOT a quote.
Quotes are often edited. I removed the middle of what a person posted so that the matter that I was commenting upon remained. Since I did cut out part of what they typed, I was clear that I removed elements without changing context.
I am old enough to have used the Dewey Decimal System to look up books for papers I wrote in school k-12. Even at the university not everything was in the computer systems, so, file cards of the DDS were in their traditional drawers, in particular in the History, Military, and Law libraries.
Very similar to using Tags to look up stories on SOL. If you are searching for stories, online or "dead tree" you may use Key Words, often identical to the Tags on SOL.
Because it seems more people are familiar with popular TV shows than many books, I gave examples of If a person were to write a Story based upon those TV shows, and remained consistent to the source material, some Tags they would likely use.
So, for print books:
Henry V: Royalty, Politics, War, Violence, Poetry, Historical, probably some others.
The Lord of the Rings; Return of the King: Fantasy, War, Violence, Magic, Tear Jerker, Romance, Ghosts, Pirates, Farming, etc
Perhaps it more common browsing books online. However in the bookstore the SciFi section has subsections such as Military SciFi, or Post Apocalypse. Romance has Urban Fantasy, Explicit, Young Adult, Western, etc.
Romance seems to be the biggest section in most bookstores. There are Tags on the shelves to help people find the variety of Romance novel they are looking for.
A tangent: some of the best writing about veterans, disabilities, physical, mental, and emotional, adapting to prosthetics, coping with PTS/PTSD, service dogs, and equine therapy, are in Romance novels! Several young lady friends have suggested books to me, or given me some to read. Better than American Sniper, one of the few books about warfare in 21st century that actually addresses PTS and other wounds and disabilities.