This is a very interesting thread. It would be a tragedy if the IMC rating was lost and I give my full support to any campaign to save it.
Fuji, for what it's worth, my interepretation of that quote is that regardless of the member state's right to issue licenses and certificates, they will only be regarded as valid if they meet the minimum standards of the Convention.
If the minimum standards are equivalent to the "IF" rating, then the IMC will not be recognised as valid.
Maybe I'm wrong