The variable DEFAULT_USER (along with ACCESS_FILE and PASSWORD_ATTEMPTS) affects AcuLaunch access security.
DEFAULT_USER holds the default user name given to AcuLaunch requesters who are not specifically mapped to a local user name in the server access file (as when the Local Username field of the access record is empty, or the value of the field is an invalid user name). Definition of DEFAULT_USER is optional. DEFAULT_USER cannot be defined as root (on UNIX systems) or Administrator (on Windows NT systems). For a description of when AcuLaunch assigns DEFAULT_USER to a requester, see Chapter 4, section 4.3.2 AcuLaunch Connection Logic.