Additional Membergroups Help

[ATLANTIS29]

ok so i made a forum with a group called "Newsletter"  it's a free select group type so that people can join and leave as they wish  what I want to know is there a way to set this so that it add them to this group in the "Additional Membergroups" area and not "Primary Membergroup" so that they do not get the group name showing in the posts 

[Allusion]

Go to the profile of each member, click the Modify Profile menu, click [ show additional groups ] next to "Additional Membergroups", select the Newsletter membergroup and click the "Change Profile" button.

[smp420]

If you edit the group and set visiblity to invisible it will have it as there additional group automatically.