Green National Convention

The Green National Convention is the presidential nominating convention of the Green Party of the United States (GPUS). Though the Green National Committee (GNC) meets annually in a "national meeting", the convention is convened by the GNC once every four years in order to nominate an official candidate in the upcoming U.S. presidential election, and to officially adopt the party platform and rules for the election cycle.

Source: Wikipedia — Green National Convention (CC BY-SA 4.0)