Now, onto the nitty gritty. How to make items, like the tank, a man cannon, or a wall, etc spawn only in the game types you want someone to be able to use them. Say you want to block a certain path in Assault, or make it so that the "lucky" spawn only happens in FFA, this is how you would do it.
The tags for "team_only" and "ffa_only" are best accessed via Slayer editing, but will still effect game types like Oddball and Headhunter (examples of other game types that use both).
This will also effect your Forge experience.
If an object is set to the "infection" tag AND game type specific is true, it will not appear if you are editing in the Invasion game type, but will still be there. It will still appear in Basic Editing, which makes for a really great way to refine maps after testing them because you can test multiple game types, make a list, and then go back and fix it.