I would have the top level tag “Rulebook” and put “Core Rulebook” as a sub-tag. Under Rulebook also have “Player Handbook”, “GM handbook” and “Splatbook”. Keep the rules together.
Also tags for your dominant systems (ex DnD, PbtA) including “System Agnostic”. Perhaps add subtags “Pre-made” and “Generators” under “Setting”. Publisher tags? Language? Decade/year of release? Have played?












So many. And the answer to all “why nots?”. Time. It’s time. So off the top of my head
Eat the Reich - “The year is 1943. You are a team of crack vampire commandos with one mission: drink all of Hitler’s blood”
Conan 2d20
Legend of the Five rings (5e)
Stoneburner - Deep Rock Galactic the TTRPG
Vaesen - Call of Cthulhu but rooted in nordic mythology
Heart the City Beneath - an award-winning complete tabletop roleplaying game about delving into a nightmare undercity that will give you everything you’ve ever dreamed of – or kill you in the process.