This is something from the EU's recent WTO modernization proposals:
Counter-notifications, i.e. notifications made by a Member on behalf of another, are a potentially powerful instrument available in various agreements. They are, however, hardly used, partly because preparing them requires a significant amount of research and intelligence.
The EU proposes to i) cooperate more with like-minded Members in preparing joint counter-notifications, ii) explore how the WTO Secretariat could be involved more, whilst guarding its neutrality towards Members, and iii) strengthen the consequences of a Member being subject to a counter-notification.
This didn't jump out at me when I first skimmed through the document, but as explained by Jakob Hanke of Politico [$], it could be important and kind of radical. The idea would be that if a Member does not notify its subsidies, and they are "counter-notified" by another Member, there would be a rebuttable presumption that they are in violation of WTO rules. With "prohibited" subsidies, I'm not sure how significant this would be, because this kind of analysis is of the usual design/structure kind. But if this would apply to "adverse effects," it sounds like a challenge to come up with the evidence to show that your subsidies are not causing any adverse effects.
I haven't seen the text of any proposals on this, and it seems like it's just at the discussion stage. But if this goes forward, it could be a pretty big deal in terms of encouraging notifications.
