user opt in to new usergroup?

[HBC]

i have another usergroup that is for a few hidden adult sections on my board.

if there a way to have a user choose by himself to be switched to that group?

[Tony G]

I don't know much about this because I've never used it before or tried it before, but there's a section in the User CP where a member can change usergroups. But I have no idea how to activate that. Maybe there's a setting when creating a new usergroupw which lets you allow members to publically change their usergroup to the one created. Take a look in there.