The tag implication #52935 fin_ring -> fin_piercing has been approved.
Reason: Not a heavily used tag as of now, but I think it has good use. Many other piercing tags feature more specific sub-tags, like ear_ring with ear_piercing, and nipple_ring with nipple_piercing. Fin piercings are most often rings, but I've seen studs and industrial-style piercings on fins as well.
EDIT: The tag implication fin_ring -> fin_piercing (forum #382242) has been approved by @slyroon.
Updated by auto moderator