All the experience codes are listed at the end of the first post.
There are TDM games (hardcore and softcore), infantry conquest ("conquest small"), king of the hill (one objective on a hill), and large conquest games (day and night) available to choose from.
If you don't want other players to join, please host with a password rather than kicking people from the game.
I haven't tackled rush or breakthrough yet, because I am not super satisfied with the compromises required, and because casual breakthrough is already available in the game and brings you towards a similar outcome.