Rengo and Pair-Go are special forms of Dragon's
Team-Go.
Rengo is the most common form of a
multi-player-game. Rengo is played by four players split into two teams, each with two players.
Pair-Go is like Rengo with the additional restriction, that each team consist of one female and one male player. Additionally, the playing rotation (order of moves) is regulated: Black lady, White lady, Black man, White man.
In handicap games, the rotation starts with the White lady playing first following the normal rotation: White lady, Black man, White man, Black lady, etc.
For more information, see:
http://senseis.xmp.net/?PairGo