When usin "Edit User" in System admin, what special permissions does it give users if you set their rank to moderator?

Is that just for the forums, or does that give them permissions to edit other modules on your XOOPS site as well?

I am asking this because I noticed that there is not a default group created for moderators in the "Groups" section of the system Admin.

I want to create forum moderators, but I don't want them to have access to amy other of the site's modules.

I know that I can do this in "groups" section, but I would like my forum mods to have the moderator stars (images) next to their avatars on the forums. Is the moderator Rank in "Edit User" just for cosmetic appeal, or are there real privileges that go along with the rank?

Thanks much