I’m curious if there is a way to tailor invitations to sub-groups so that an invitee can only join a subset of the subgroups of a main group. I understand that you must be a member of the main group to be a member of any subgroup, but right now, it appears that the only way to allow membership to a subset of subgroups is to invite to the main group and then, after the member joins that, either allow them to join the groups you want them in, and reject their attempts to join the others, or open subgroups under Admin and check the appropriate boxes. Note that I realize that the groups all have to require permission to join to have any hope of keeping people out of places that they don’t belong.

As best I can tell, other then requiring approval to join and rejecting the request, there isn’t any way to specifically invite to a subgroup and restrict other subgroups from that member… right?

And just so you understand, let me explain the situation. In the interests of consolidating the administrative mailing lists for our organization (The Pennsylvania Railroad Technical and Historical Society) I created a main admin list with subgroups for our Board of Directors, Modeling Committee, Paint Committee, etc… ?Some discussions are confidential and members of one committee should not necessarily be able to see the discussions of the others. That works great with the structure of making the posts private to the subgroup… but it’s the process of membership of subsets of those groups that is the issue.