Workstations can be restricted to a limited range of session clearances and labels. For example, a workstation in a lobby might be limited to PUBLIC labels only. If the label or session clearance that you specify is not accepted, check with an administrator to determine if the workstation is restricted.
In a standard login, the shell initialization files are sourced at startup to provide a customized environment. In a failsafe login, the default values are applied to your system and no shell initialization files are sourced.
In Trusted Extensions, a failsafe login is protected. Only the root account can access a failsafe login.