A deputy leader is a player who has been designated by the leader as the second most important player in the team. They have the abillity to change the team settings, such as the team description, required level, badge and type, or remove other players from the team (except for the team leader). They cannot assign other deputies, however.
Important: If a leader leaves the team or doesn't pass any levels for 6 months, the leadership is transferred to the next person who joined the team after the leader (as long as they're active), or to the deputy if there is one.