The repository administrator is responsible for creating groups of users in the repository. Users are added to groups in order to simplify the granting of rights and permissions and the use of profiles. You can create hierarchies of groups. For example, you could insert the Designers, Quality Assurance, and Documentation groups into the R&D group, to which you assign permissions to documents that all these groups must use.
Administrators, [ADMN] - has all available rights.
All users [PUBLIC] - has the Connect right and Read permission on the repository root (see Granting Access Permissions on Repository Items). All users belong to this group and can thus connect to the repository and check out any document.
External users [EXTERNAL] - has the Connect right. Remote LDAP users (see Controlling Repository Access with LDAP) are automatically added to this group when they connect for the first time.