Are they the owners of their groups (identified by star next to their name in group members list in Persona)? Because even if they're not moderators I believe group owners are able to add people to their group.
How to add a footer?
I know it good that I can place the footer from admin, but I am not sure how to write a html to show it.
Simply, how to add a footer just like this forum?
It's a global widget placed in footer.tpl