Entity collision issues/question

Is there a way to make a entity not collide with a certain team?

For example, I have a entity (test_ent) with the radio model from css and two teams (TEAM1 and TEAM2). test_ent belongs to TEAM1 and should be nocollided with the members of TEAM1 but TEAM2 should be collide with it. Or, is there a way to have a COLLISION_ enum that allows for triggering (ENT:Touch) but is nocollided for players?

Right now I am using SetCollisionGroup(0) which makes it solid, but when I try to set it to 20 (collide only with world) I cannot trigger it with ENT:Touch

Also, is there a COLLISION_ enum that makes a prop nocollide with everything, even bullets? The prop has to be shared (cannot be a CreateClientsideProp or whatever it is) as it is part of the game and certain things rely on it.

READ DESCRIPTION: http://wiki.garrysmod.com/page/GM/ShouldCollide

Yeah, tried that. Didn’t work. Moving on.