The bulk update request #12705 has been rejected.
create alias hair_rings -> hair_ring
While a lot of characters have multiple hair rings, there are some that are typically portrayed with just a single one, like Alina Gray or Asari Nanami.
Another option would be to separate these into more tags, similar to hair buns - "hair_ring" as the catch-all, and then tags like single_hair_ring and double_hair_rings/twin_hair_rings (and multiple_hair_rings for 3+) emerging from it, implicating it.