 Typical complicating factors that make an employer's status ambiguous include the extensive use of part-time workers, existence of multiple entities that need to be grouped as a "single employer", and significant employee churn.The U.S. Department of Labor does not require all petitions to be in the public access file, but it does require the public access file to contain the list of all exempt nonimmigrants.However, if "all" petitions filed by the employer are for exempt nonimmigrants, then this list need not be maintained.