im thinking about an ally add for the TDM mod, so every time you choose a team a button saying "set ally" apears in the team config window, the one that shows the equipment and uniform, when you click that button, another window appears showing the other teams, you pick one or more then you click another buton below to save the changes,
if you kill a member of an allied team it will count as a team mate, so if you cant kill team mates, you cant neither kill allies