Do you mean when you press 'X' on an object and there is the symmetry option? If you put it on symmetrical it will only show up on symmetrical gametypes; mulit-flag, multi-bomb, etc..., if you put it on asymmetrical it will only show up on non-symmetrical gemtypes; one-flag, zombies, one-bomb, juggernaut. Putting the option on 'Both' will allow the object to appear during any gametype.