Terms used in Tags
I used some general terms when tagging posts, so I don't end up with 4 different tags that all mean the same thing.
magic-user: mage, wizard, sorcerer, etc.
sea-people: mermaids, sea elves, fish-people, selkies, etc.
demon: demon, imp, goblin, etc.
quest: hero's epic quest, ordinary person's search, detective's investigation
mutant: humans with special abilities (telepathy, seeing the past/future, etc.) or humans with physical mutations (night vision, wings, etc.)
The 'mutant' tag does not include things like werewolves, which are considered a different species from humans, for the purposes of tagging.
Writing Terms
MC: main character
FMC, MMC: female MC, male MC
C1, C2: character1, character2
MS: manuscript
That's all I can think of. If I missed anything, let me know.