Please discuss this page and see if this perhaps can be codified. Gating has a Wiki entry here:
The idea of gating is to have a subset of a drop that is distinct enough and to cover games like Bosworth, B-Class+ IAGO Chess, or Seirawan chess. It has to do with either a piece teleporting or droping another piece in from reserve. Please discuss and review. When tied to a drop, the drop is connected to an onboard piece somehow. If it doesn't have this connection, it is a straight drop. One can argue this really isn't new, and that is true. Promotion is arguably a form of gating, as would be castling.