Tradition 4... autonomy. The group conscience is just that... what the group has decided what it will and not do. If you want what a group has and does, you should belong to it. If you want what a group has and does, you should do what the group does.
If the group does what you do not like, try to change it or find another group.
In my group, we go beyond the "blue card" for closed meetings. We say, "We are a closed group of Alcoholics Anonymous and ask that you introduce yourself as alcoholic only." or something like that. But if we see a new person come to our group, we find out if they are in the right place up front and if not, direct them elsewhere if need be.