Opinion modifier of reappearing countries
Countries can disappear when they lose all of their lands.
However, they can be again by releasing them (as vassals or through a peace deal, big enough revolts).
How is the opinion modifier of a country which existed, disappeared and reappeared? Is the opinion recalculated?
Each tag (country), if removed from the game keeps their opinion modifiers till end of month.
If country ceases to exist on, say, April 10th in a peace deal when you full annex them and later you release them on the May 1st - they will lose all opinion modifiers they had before the full annexation.