Maybe we'll implement them later, or maybe not, but let's make the statu
quo clear for now.

Author: Lætitia Avrot, Patrick Francelle
Reviewers: too many to list
Discussion: https://postgr.es/m/CAB_COdhUuzNFOJfc7SNNso5rOuVA3ui93KMVunEM8Yih+K5A6A@mail.gmail.com