On the Green Card for motor insurance there is a grid with the abbreviations of loads of different countries. As far as I understand it (and this seems illogically hard to verify), if a country is not crossed out then you have the minimum 3rd-party insurance that is legally necessary to drive your vehicle in that country. If the country _is_ crossed out, then you do not have the minimum insurance to drive your vehicle in that country and you'd need to stop at the border and buy supplementary insurance before crossing.
I also understand that the green card has nothing to do with the fully-comp part of the insurance that is detailed elsewhere in the policy.
Is this all correct?
Because both my insurance broker and underwriter seem to believe something very different, though they are completely unable to explain how they think a green card works and it's left me very confused.