[Koha] User profiles ?

Dear all, Does Koha have some notion of user group ? What is meant here by group is the ability to express that a user belongs to one or several groups, and then writing templates or script that behave differently according to which groups the user belongs to. The notion of group is not the one of category, because a user can, as far as I know, belong to only one user category. Many thanks in advance for any hint ! Sébastien.