Gangs in haiti have creole names. Many gangs got their sector name in their neighborhoods. You got Delma 16 gang, Delma 9 gang etc.
G9 is an alliance that started with 9 gangs. So they choose G9 from the inspiration of the G7(before G8) international group of developed countries. So Group 9
G-Pep, « pep » mean people in creole, so it is the People Group.