The Underworld Council
Once or twice a year or so, the heads of the Nine Gangs of Gotham meet, in disguise, at a neutral location. There is little formal organization or rule-making power to the meeting, but it does allow the leaders to speak freely and has resulted in some deals in regards to territories and rackets. It was at such a meeting that a potential war between the Free Men and The East Siders Gang was averted over the Bucca De Fagaccini incident, and at a similar meeting the informal truce with The Bristol County Sheriff's Office was thought up.
Some gang leaders (especially the Falcone Family) dream of turning the council into a sort of United Underworld, or mafia like syndicate, but there is little chance of that now. The All Americans gang leaders only grudgingly show up at the council, feeling that the other gangs should show allegiance to them.