Ultiduo

Ultiduo is a competitive format consisting of two players on each team, usually a Soldier and a Medic.
This gamemode is usually played on small koth maps made specifically for it and often used by 6v6 players to practice.

Weapons

Typically since this is played by friends with friends there is no real banned weapon list. With that being said from personal experiences I can say some weapons do make Ultiduo less fun to play and these weapons are usually banned in tournaments.
Soldier Liberty Launcher
Direct Hit

Maps

ultiduo_baloo
koth_ultiduo_r_b7