M3 uses an elaborate, hierarchical  security  scheme that enables the librarian to assign levels of access for Cataloging, Circulation,  OPAC, and database maintenance features. Security in M3 is implemented through the use of the M3 Group Editor. The Group Editor creates, customizes,  and modifies the group permissions required to gain access to M3 functions. Groups are created with customized  sets of parameters and privileges. The three default group types are patron, item, and special reserve. An unlimited number of each group  type can be created. Items and patrons  can be moved in batches to different  groups  for quick updating.