Geopolitical bloc is a union of states with common goals and ideas.
Bloc can be created by any state leader. After that he can change its title, logo and description. In blocs list you can only find blocs that include not less than 2 states.
To join an existing bloc requires the application of state leader, which then will be voted for by other leaders in this bloc. States from the same bloc can't declare wars to each other.
Voting on this regulations is available only to leaders of states.
You can also check out special map filter, which shows regions of each bloc in different color.